Ear and Hearing

Ear and Hearing

CEDRA: A Tool to Help Consumers Assess Risk for Ear Disease

01-11-2019 – Klyn, Niall A. M.; Kleindienst Robler, Samantha; Bogle, Jamie; Alfakir, Razan; Nielsen, Donald W.; Griffith, James W.; Carlson, Deborah L.; Lundy, Larry; Dhar, Sumitrajit; Zapala, David A.

Journal Article

This article introduces the Consumer Ear Disease Risk Assessment (CEDRA) tool. CEDRA is a brief questionnaire designed to screen for targeted ear diseases. It offers an opportunity for consumers to self-screen for disease before seeking a hearing device and may be used by clinicians to help their patients decide the appropriate path to follow in hearing healthcare. Here we provide highlights of previously published validation in the context of a more thorough description of CEDRA’s development and implementation. CEDRA’s sensitivity and specificity, using a cut-off score of 4 or higher, was 90% and 72%, respectively, relative to neurotologist diagnoses in the initial training sample used to create the scoring algorithm (n = 246). On a smaller independent test sample (n = 61), CEDRA’s sensitivity and specificity were 76% and 80%, respectively. CEDRA has readability levels similar to many other patient-oriented questionnaires in hearing healthcare, and informal reports from pilot CEDRA-providers indicate that the majority of patients can complete it in less than 10 min. As the hearing healthcare landscape changes and provider intercession is no longer mandated, CEDRA provides a measure of safety without creating a barrier to access.

Reliability of Measures Intended to Assess Threshold-Independent Hearing Disorders

01-11-2019 – Kamerer, Aryn M.; Kopun, Judy G.; Fultz, Sara E.; Neely, Stephen T.; Rasetshwane, Daniel M.

Journal Article

Objectives: Recent animal studies have shown that noise exposure can cause cochlear synaptopathy without permanent threshold shift. Because the noise exposure preferentially damaged auditory nerve fibers that processed suprathreshold sounds (low-spontaneous rate fibers), it has been suggested that synaptopathy may underlie suprathreshold hearing deficits in humans. Recently, several researchers have suggested measures to identify the pathology or pathologies underlying suprathreshold hearing deficits in humans based on results from animal studies; however, the reliability of some of these measures have not been assessed. The purpose of this study was to assess the test–retest reliability of measures that may have the potential to relate suprathreshold hearing deficits to site(s)-of-lesion along the peripheral auditory system in humans.
Design: Adults with audiometric normal hearing were tested on a battery of behavioral and physiologic measures that included (1) thresholds in quiet (TIQ), (2) thresholds in noise (TIN), (3) frequency-modulation detection threshold (FMDT), (4) word recognition in four listening conditions, (5) distortion-product otoacoustic emissions (DPOAE), (6) middle ear muscle reflex (MEMR), (7) tone burst-elicited auditory brainstem response (tb
ABR), and (8) speech-evoked ABR (s
ABR). Data collection for each measure was repeated over two visits separated by at least one week. The residuals of the correlation between the suprathreshold measures and TIQ serve as functional and quantitative proxies for threshold-independent hearing disorders because they represent the portion of the raw measures that is not dependent on TIQ. Reliability of the residual measures was assessed using intraclass correlation (ICC).
Results: Reliability for the residual measures was good (ICC ≥ 0.75) for FMDT, DPOAEs, and MEMR. Residual measures showing moderate reliability (0.5 ≤ ICC < 0.75) were tb
ABR wave I amplitude, TIN, and word recognition in quiet, noise, and time-compressed speech with reverberation. Wave V of the tb
ABR, waves of the s
ABR, and recognition of time-compressed words had poor test–retest reliability (ICC < 0.5).
Conclusions: Reliability of residual measures was mixed, suggesting that care should be taken when selecting measures for diagnostic tests of threshold-independent hearing disorders. Quantifying hidden hearing loss as the variance in suprathreshold measures of auditory function that is not due to TIQ may provide a reliable estimate of threshold-independent hearing disorders in humans.

Understanding Variability in Individual Response to Hearing Aid Signal Processing in Wearable Hearing Aids

01-11-2019 – Souza, Pamela; Arehart, Kathryn; Schoof, Tim; Anderson, Melinda; Strori, Dorina; Balmert, Lauren

Journal Article

Objectives: Previous work has suggested that individual characteristics, including amount of hearing loss, age, and working memory ability, may affect response to hearing aid signal processing. The present study aims to extend work using metrics to quantify cumulative signal modifications under simulated conditions to real hearing aids worn in everyday listening environments. Specifically, the goal was to determine whether individual factors such as working memory, age, and degree of hearing loss play a role in explaining how listeners respond to signal modifications caused by signal processing in real hearing aids, worn in the listener’s everyday environment, over a period of time.
Design: Participants were older adults (age range 54–90 years) with symmetrical mild-to-moderate sensorineural hearing loss. We contrasted two distinct hearing aid fittings: one designated as mild signal processing and one as strong signal processing. Forty-nine older adults were enrolled in the study and 35 participants had valid outcome data for both hearing aid fittings. The difference between the two settings related to the wide dynamic range compression and frequency compression features. Order of fittings was randomly assigned for each participant. Each fitting was worn in the listener’s everyday environments for approximately 5 weeks before outcome measurements. The trial was double blind, with neither the participant nor the tester aware of the specific fitting at the time of the outcome testing. Baseline measures included a full audiometric evaluation as well as working memory and spectral and temporal resolution. The outcome was aided speech recognition in noise.
Results: The two hearing aid fittings resulted in different amounts of signal modification, with significantly less modification for the mild signal processing fitting. The effect of signal processing on speech intelligibility depended on an individual’s age, working memory capacity, and degree of hearing loss. Speech recognition with the strong signal processing decreased with increasing age. Working memory interacted with signal processing, with individuals with lower working memory demonstrating low speech intelligibility in noise with both processing conditions, and individuals with higher working memory demonstrating better speech intelligibility in noise with the mild signal processing fitting. Amount of hearing loss interacted with signal processing, but the effects were small. Individual spectral and temporal resolution did not contribute significantly to the variance in the speech intelligibility score.
Conclusions: When the consequences of a specific set of hearing aid signal processing characteristics were quantified in terms of overall signal modification, there was a relationship between participant characteristics and recognition of speech at different levels of signal modification. Because the hearing aid fittings used were constrained to specific fitting parameters that represent the extremes of the signal modification that might occur in clinical fittings, future work should focus on similar relationships with more diverse types of signal processing parameters.

Mechanisms of Localization and Speech Perception with Colocated and Spatially Separated Noise and Speech Maskers Under Single-Sided Deafness with a Cochlear Implant

01-11-2019 – Dirks, Coral; Nelson, Peggy B.; Sladen, Douglas P.; Oxenham, Andrew J.

Journal Article

Objectives: This study tested listeners with a cochlear implant (CI) in one ear and acoustic hearing in the other ear, to assess their ability to localize sound and to understand speech in collocated or spatially separated noise or speech maskers.
Design: Eight CI listeners with contralateral acoustic hearing ranging from normal hearing to moderate sensorineural hearing loss were tested. Localization accuracy was measured in five of the listeners using stimuli that emphasized the separate contributions of interaural level differences (ILDs) and interaural time differences (ITD) in the temporal envelope and/or fine structure. Sentence recognition was tested in all eight CI listeners, using collocated and spatially separated speech-shaped Gaussian noise and two-talker babble. Performance was compared with that of age-matched normal-hearing listeners via loudspeakers or via headphones with vocoder simulations of CI processing.
Results: Localization improved with the CI but only when high-frequency ILDs were available. Listeners experienced no additional benefit via ITDs in the stimulus envelope or fine structure using real or vocoder-simulated CIs. Speech recognition in two-talker babble improved with a CI in seven of the eight listeners when the target was located at the front and the babble was presented on the side of the acoustic-hearing ear, but otherwise showed little or no benefit of a CI.
Conclusion: Sound localization can be improved with a CI in cases of significant residual hearing in the contralateral ear, but only for sounds with high-frequency content, and only based on ILDs. In speech understanding, the CI contributed most when it was in the ear with the better signal to noise ratio with a speech masker.

Bone Conduction Amplification in Children: Stimulation via a Percutaneous Abutment versus a Transcutaneous Softband

01-11-2019 – Pittman, Andrea L.

Journal Article

Objectives: Research suggests that the speech perception of children using bone conduction amplification improves if the device is coupled to an implanted abutment rather than to a softband. The purpose of the present study was to determine if the benefit of direct stimulation via an abutment is limited to small improvements in speech perception or if similar or greater benefits occur for other auditory tasks important for learning and communication.
Design: Fourteen children (7 to 15 years of age) with bilateral conductive and three children with unilateral conductive or sensorineural hearing loss were enrolled. Each child completed four tasks while using a bone conduction device coupled to an implanted abutment and with the device coupled to a softband. The two devices were worn at the same time and activated one at a time for testing. The children completed four tasks under each coupling condition: (a) a traditional word recognition task, (b) an auditory lexical decision task in which the children repeated aloud, and indicated the category of, real and nonsense words, (c) a nonsense-word detection task which required the children to identify nonsense words within short sentences, and (d) a rapid word learning task in which the children learned to associate nonsense words with novel images.
Results: Regression analyses revealed that age, duration of device use, in-situ hearing thresholds, or device output did not account for a significant portion of the variability in performance for any of the four tasks. Repeated-measures analysis of variance revealed significant increases in word recognition with the abutment as well as significantly better performance for the lexical decision and word learning tasks. The data indicated that the children with the poorest performance with the softband tended to benefit most with the abutment. Also, the younger children showed improved performance for more tasks with the abutment than the older children. No difference between coupling conditions was observed for nonsense-word detection.
Conclusions: The improved recognition of familiar words, categorization and repetition of nonsense words, and speed of word learning with the abutment suggests that direct stimulation provides a higher-quality signal than indirect stimulation through a softband. Because these processes are important for vocabulary acquisition and language development, children may experience long-term benefits of direct stimulation for academic, social, and vocational purposes in addition to immediate improvement in communication.

Factors Affecting Bimodal Benefit in Pediatric Mandarin-Speaking Chinese Cochlear Implant Users

01-11-2019 – Liu, Yang-Wenyi; Tao, Duo-Duo; Chen, Bing; Cheng, Xiaoting; Shu, Yilai; Galvin, John J. III; Fu, Qian-Jie

Journal Article

Objectives: While fundamental frequency (F0) cues are important to both lexical tone perception and multitalker segregation, F0 cues are poorly perceived by cochlear implant (CI) users. Adding low-frequency acoustic hearing via a hearing aid in the contralateral ear may improve CI users’ F0 perception. For English-speaking CI users, contralateral acoustic hearing has been shown to improve perception of target speech in noise and in competing talkers. For tonal languages such as Mandarin Chinese, F0 information is lexically meaningful. Given competing F0 information from multiple talkers and lexical tones, contralateral acoustic hearing may be especially beneficial for Mandarin-speaking CI users’ perception of competing speech.
Design: Bimodal benefit (CI+hearing aid – CI-only) was evaluated in 11 pediatric Mandarin-speaking Chinese CI users. In experiment 1, speech recognition thresholds (SRTs) were adaptively measured using a modified coordinated response measure test; subjects were required to correctly identify 2 keywords from among 10 choices in each category. SRTs were measured with CI-only or bimodal listening in the presence of steady state noise (SSN) or competing speech with the same (M+M) or different voice gender (M+F). Unaided thresholds in the non-CI ear and demographic factors were compared with speech performance. In experiment 2, SRTs were adaptively measured in SSN for recognition of 5 keywords, a more difficult listening task than the 2-keyword recognition task in experiment 1.
Results: In experiment 1, SRTs were significantly lower for SSN than for competing speech in both the CI-only and bimodal listening conditions. There was no significant difference between CI-only and bimodal listening for SSN and M+F (p > 0.05); SRTs were significantly lower for CI-only than for bimodal listening for M+M (p 0.05). Unaided thresholds in the non-CI ear were positively correlated with bimodal SRTs for M+M (p 0.05 in all cases). In experiment 2, SRTs were significantly lower with two than with five keywords (p < 0.05). A significant bimodal benefit was observed only for the 5-keyword condition (p < 0.05).
Conclusions: With the CI alone, subjects experienced greater interference with competing speech than with SSN and were unable to use voice gender difference to segregate talkers. For the coordinated response measure task, subjects experienced no bimodal benefit and even bimodal interference when competing talkers were the same voice gender. A bimodal benefit in SSN was observed for the five-keyword condition but not for the two-keyword condition, suggesting that bimodal listening may be more beneficial as the difficulty of the listening task increased. The present data suggest that bimodal benefit may depend on the type of masker and/or the difficulty of the listening task.

Age-Related Changes in Temporal Resolution Revisited: Electrophysiological and Behavioral Findings From Cochlear Implant Users

01-11-2019 – Mussoi, Bruna S. S.; Brown, Carolyn J.

Journal Article

Objectives: The mechanisms underlying age-related changes in speech perception are still unclear, most likely multifactorial and often can be difficult to parse out from the effects of hearing loss. Age-related changes in temporal resolution (i.e., the ability to track rapid changes in sounds) have long been associated with speech perception declines exhibited by many older individuals. The goals of this study were as follows: (1) to assess age-related changes in temporal resolution in cochlear implant (CI) users, and (2) to examine the impact of changes in temporal resolution and cognition on the perception of speech in noise. In this population, it is possible to bypass the cochlea and stimulate the auditory nerve directly in a noninvasive way. Additionally, CI technology allows for manipulation of the temporal properties of a signal without changing its spectrum.
Design: Twenty postlingually deafened Nucleus CI users took part in this study. They were divided into groups of younger (18 to 40 years) and older (68 to 82 years) participants. A cross-sectional study design was used. The speech processor was bypassed and a mid-array electrode was used for stimulation. We compared peripheral and central physiologic measures of temporal resolution with perceptual measures obtained using similar stimuli. Peripherally, temporal resolution was assessed with measures of the rate of recovery of the electrically evoked compound action potential (ECAP), evoked using a single pulse and a pulse train as maskers. The acoustic change complex (ACC) to gaps in pulse trains was used to assess temporal resolution more centrally. Psychophysical gap detection thresholds were also obtained. Cognitive assessment included two tests of processing speed (Symbol Search and Coding) and one test of working memory (Digit Span Test). Speech perception was tested in the presence of background noise (Quick
SIN test). A correlational design was used to explore the relationship between temporal resolution, cognition, and speech perception.
Results: The only metric that showed significant age effects in temporal processing was the ECAP recovery function recorded using pulse train maskers. Younger participants were found to have faster rates of neural recovery following presentation of pulse trains than older participants. Age was not found to have a significant effect on speech perception. When results from both groups were combined, digit span was the only measure significantly correlated with speech perception performance.
Conclusions: In this sample of CI users, few effects of advancing age on temporal resolution were evident. While this finding would be consistent with a general lack of aging effects on temporal resolution, it is also possible that aging effects are influenced by processing peripheral to the auditory nerve, which is bypassed by the CI. However, it is known that cross-fiber neural synchrony is improved with electrical (as opposed to acoustic) stimulation. This change in neural synchrony may, in turn, make temporal cues more robust/perceptible to all CI users. Future studies involving larger sample sizes should be conducted to confirm these findings. Results of this study also add to the growing body of literature that suggests that working memory is important for the perception of degraded speech.

Effects of Forward- and Emitted-Pressure Calibrations on the Variability of Otoacoustic Emission Measurements Across Repeated Probe Fits

01-11-2019 – Maxim, Tom; Shera, Christopher A.; Charaziak, Karolina K.; Abdala, Carolina

Journal Article

Objective: The stimuli used to evoke otoacoustic emissions (OAEs) are typically calibrated based on the total SPL measured at the probe microphone. However, due to the acoustics of the ear-canal space (i.e., standing-wave interference), this method can underestimate the stimulus pressure reaching the tympanic membrane at certain frequencies. To mitigate this effect, stimulus calibrations based on forward pressure level (FPL) can be applied. Furthermore, the influence of ear-canal acoustics on measured OAE levels can be compensated by expressing them in emitted pressure level (EPL). To date, studies have used artificial shallow versus deep probe fits to assess the effects of calibration method on changes in probe insertion. In an attempt to better simulate a clinical setting, the combined effects of FPL calibration of stimulus level and EPL compensation of OAE level on response variability during routine (noncontrived) probe fittings were examined.
Design: The distortion component of the distortion-product OAE (DPOAE) and the stimulus-frequency OAE (SFOAE) were recorded at low and moderate stimulus levels in 20 normal-hearing young-adult subjects across a five-octave range. In each subject, three different calibration approaches were compared: (1) the conventional SPL-based stimulus calibration with OAE levels expressed in SPL; (2) FPL stimulus calibration with OAEs expressed in SPL; and (3) FPL stimulus calibration with OAEs expressed in EPL. Test and retest measurements were obtained during the same session and, in a subset of subjects, several months after the initial test. The effects of these different procedures on the inter- and intra-subject variability of OAE levels were assessed across frequency and level.
Results: There were no significant differences in the inter-subject variability of OAE levels across the three calibration approaches. However, there was a significant effect on OAE intra-subject variability. The FPL/EPL approach resulted in the overall lowest test-rest differences in DPOAE level for frequencies above 4 k
Hz, where standing-wave interference is strongest. The benefit was modest, ranging on average from 0.5 to 2 d
B and was strongest at the lower stimulus level. SFOAE level variability did not show significant differences among the three procedures, perhaps due to insufficient signal-to-noise ratio and nonoptimized stimulus levels. Correlations were found between the short-term replicability of DPOAEs and the benefit derived from the FPL/EPL procedure: the more variable the DPOAE, the stronger the benefit conferred by the advanced calibration methods.
Conclusions: Stimulus and response calibration procedures designed to mitigate the effects of standing-wave interference on both the stimulus and the OAE enhance the repeatability of OAE measurements and reduce their dependence on probe position, even when probe shifts are small. Modest but significant improvements in short-term test-retest repeatability were observed in the mid- to high-frequency region when using combined FPL/EPL procedures. The authors posit that the benefit will be greater in a more heterogeneous group of subjects and when different testers participate in the fitting and refitting of subjects, which is a common practice in the audiology clinic. The impact of calibration approach on OAE inter-subject variability was not significant, possibly due to a homogeneous subject population and because factors other than probe position are at play.

Childhood Sensorineural Hearing Loss and Educational Attainment in Adulthood: Results From the HUNT Study

01-11-2019 – Idstad, Mariann; Engdahl, Bo

Journal Article

Objectives: Although the educational achievement gap between people without hearing loss and people with hearing loss is well-documented, few studies are based on large, nonclinical samples. The present study aims to investigate the educational attainment among Norwegian adults diagnosed with sensorineural hearing loss as children, compared with a matched control group of people without hearing loss.
Design: A prospective cohort design was applied. Between 1954 and 1986, the children in the first, fourth, and/or seventh grade in all primary schools in Nord-Trøndelag County participated in the School Hearing Investigation in Nord-Trøndelag, in which they underwent audiometric screening. Those with positive results had their hearing further tested by means of pure tone audiometry at 0.25, 0.5, 1, 2, 4, and 8 k
Hz with air- and bone-conduction thresholds, as well as a full examination by an ear, nose, and throat (ENT) specialist. In the present study, 216 persons were classified with moderate-severe hearing loss (41 to 100 d
B HL), 293 with mild hearing loss (26 to 40 d
B HL), and 240 with slight hearing loss (16 to 25 d
B HL). Age-matched controls were recruited from the Norwegian Health Study, which was conducted in the same county. A total of 48,606 people participated in the present study. Data on educational attainment up to 2014 was provided by Statistics Norway. Control variables comprised sex, age, mothers’, and fathers’ education. The relation between childhood sensorineural hearing loss and educational attainment was tested by means of multinomial logistic regression models; first for the total sample (born between 1941 and 1979), and then for two different birth cohorts born between 1941 and 1959 and between 1960 and 1979.
Results: Percentwise, the educational attainment level in general has increased, both among people without hearing loss and people with hearing loss, and especially for women. However, 27.5% of people without hearing loss obtained higher education, whereas the corresponding numbers for those with mild or moderate-severe hearing loss were 18.8%, and 21.3%, respectively. The results from the regression analyses showed that in the total sample, compared with having primary education, people with moderate-severe or mild hearing loss were about half as likely to achieve higher education as people without hearing loss (odds ratio (OR) = 0.63 and 0.49, respectively). An interaction term between sensorineural hearing loss and sex was specified but it was not significant. In the older cohort, we found a significant association between mild hearing loss and higher education (OR = 0.40), and between moderate-severe hearing loss and secondary education (OR = 0.65). In the younger cohort, there was a significant association between mild hearing loss and higher education (OR = 0.56) and between slight hearing loss and secondary education (OR = 0.61).
Conclusions: The results from this study indicate that the achievement gap between people without hearing loss and those with hearing loss remains. Future studies should try to pinpoint what might be hindering people with slight, mild, moderate, or severe hearing loss in pursuing higher education. Parents, health personnel, institutions for higher education, and policy makers alike should take this into consideration when making plans and policies.

Effect of Compression on Musical Sound Quality in Cochlear Implant Users

01-11-2019 – Gilbert, Melanie; Jiradejvong, Patpong; Limb, Charles

Journal Article

Objectives: Cochlear implant (CI) users frequently report poor sound quality while listening to music, although the specific parameters responsible for this loss of sound quality remain poorly understood. Audio compression, which reduces the dynamic range (DR) for a given sound, is a ubiquitous component of signal processing used by both CI and hearing aid technology. However, the relative impact of compression for acoustic and electric hearing on music perception has not been well studied, an important consideration especially given that most compression algorithms in CIs were developed to optimize speech perception. The authors hypothesized that normal-hearing (NH) listeners would detect increased levels of compression more easily than CI users, but that both groups would perceive a loss of sound quality with increasing compression levels.
Design: The present study utilizes the Cochlear Implant-MUltiple Stimulus with Hidden Reference and Anchor to evaluate the listener sensitivity to increasing levels of compression applied to music stimuli. The Cochlear Implant-MUltiple Stimulus with Hidden Reference and Anchor is a tool used to assess relative changes in the perceived sound quality of music across increasingly degraded listening conditions, in both CI and NH subjects. In this study, the authors applied multiple iterations of an aggressive compression algorithm to the music clips using Adobe Audition. The test conditions included 1, 3, 5, and 20 iterations sound tokens, with the 20-iteration samples serving as the Anchor stimuli. The compressed excerpts were 5 sec in length, with five clips for each of the five common musical genres (i.e., Classical, Jazz, Country, Rock, and Hip-Hop). Subjects were also presented with a Reference excerpt, which was the original music clip without any additional compression applied. CI recipients (n = 7, 11 ears) and NH listeners (n = 10) were asked to rate the sound quality of additionally compressed music as compared to the Reference.
Results: Although both NH and CI groups could detect sound quality differences as a function of compression level, the discriminatory ability of the CI group was blunted compared to the NH group. The CI group had less variability in their responses and overall demonstrated reduced sensitivity to deterioration caused by excessive levels of compression. On average, the CI group rated the Anchor condition as only “Slightly worse” than the Reference. The music clips that were most affected by the compression were from Jazz and Hip-Hop genres and less so for Rock and Country clips. Corollary to this was a small but statistically significant impact of DR of the music clips on sound quality ratings, with narrower DR showing an association with poorer ratings.
Conclusions: These results indicate that CI users exhibit less sensitivity to sound quality changes in music attributable to high levels of compression. These findings may account for another contributing factor to the generally poor music perception observed in CI users, particularly when listening to commercially recorded music.

Neural Indices of Vowel Discrimination in Monolingual and Bilingual Infants and Children

01-11-2019 – Yu, Yan H.; Tessel, Carol; Han, Henry; Campanelli, Luca; Vidal, Nancy; Gerometta, Jennifer; Garrido-Nag, Karen; Datta, Hia; Shafer, Valerie L.

Journal Article

Objectives: To examine maturation of neural discriminative responses to an English vowel contrast from infancy to 4 years of age and to determine how biological factors (age and sex) and an experiential factor (amount of Spanish versus English input) modulate neural discrimination of speech.
Design: Event-related potential (ERP) mismatch responses (MMRs) were used as indices of discrimination of the American English vowels ε versus I in infants and children between 3 months and 47 months of age. A total of 168 longitudinal and cross-sectional data sets were collected from 98 children (Bilingual Spanish–English: 47 male and 31 female sessions; Monolingual English: 48 male and 42 female sessions). Language exposure and other language measures were collected. ERP responses were examined in an early time window (160 to 360 msec, early MMR e
MMR) and late time window (400 to 600 msec, late MMR).
Results: The e
MMR became more negative with increasing age. Language experience and sex also influenced the amplitude of the e
MMR. Specifically, bilingual children, especially bilingual females, showed more negative e
MMR compared with monolingual children and with males. However, the subset of bilingual children with more exposure to English than Spanish compared with those with more exposure to Spanish than English (as reported by caretakers) showed similar amplitude of the e
MMR to their monolingual peers. Age was the only factor that influenced the amplitude of the late MMR. More negative late MMR was observed in older children with no difference found between bilingual and monolingual groups.
Conclusions: Consistent with previous studies, our findings revealed that biological factors (age and sex) and language experience modulated the amplitude of the e
MMR in young children. The early negative MMR is likely to be the mismatch negativity found in older children and adults. In contrast, the late MMR amplitude was influenced only by age and may be equivalent to the Nc in infants and to the late negativity observed in some auditory passive oddball designs.

The Effect of Otoacoustic Emission Stimulus Level on the Strength and Detectability of the Medial Olivocochlear Reflex

01-11-2019 – Lewis, James D.

Journal Article

Objectives: Previous work demonstrates the importance of a high signal to noise ratio (SNR) when using transient evoked otoacoustic emissions (TEOAEs) to assay the medial olivocochlear reflex (MOCR). Increasing stimulus level provides one means to increase TEOAE SNR. However, this may come at the expense of a smaller MOCR effect. It is not clear whether the gain in SNR associated with the use of higher stimulus levels outweighs the disadvantage of a potentially smaller MOCR effect. The present study investigated the strength and detectability of the MOCR when assayed using TEOAEs at different stimulus levels. The hypothesis was that although the strength of the MOCR decreases with increasing stimulus level, the occurrence of statistically significant MOCR effects increases due to an increase in TEOAE SNR.
Design: Twenty-five young adult females with normal hearing participated in the study. TEOAEs were measured in the right ear with and without broadband noise presented in the left ear. The strength of the MOCR was quantified as the percent difference in the TEOAE between the contralateral noise and quiet conditions. Statistical bootstrapping was used to detect significant MOCR effects in individual subjects across different frequency bands and stimulus levels. The relationship between a detectable MOCR (response variable) and frequency, stimulus level, TEOAE SNR, MOCR strength, and subject (predictor variables) was evaluated using generalized linear mixed-effect models.
Results: The number of statistically significant MOCR effects increased with stimulus level at all frequencies. Occurrence was highest for the 2-k
Hz TEOAE frequency band and lowest for the 4-k
Hz frequency band. The strength of the MOCR decreased with increasing click level. TEOAE SNR, MOCR strength, and stimulus level were significant predictors of a detectable MOCR: The likelihood of a detectable MOCR increased with TEOAE SNR, MOCR strength, and stimulus level.
Conclusions: Despite a reduction in the strength of the MOCR with increasing stimulus level, the detectability of the MOCR increased. This is due, in part, to an increase in TEOAE SNR with stimulus level. For clinical implementation of TEOAE-based MOCR assays, achieving a high SNR is necessary to permit the detection of the MOCR in individual patients.

Interactions Between Item Set and Vocoding in Serial Recall

01-11-2019 – Bosen, Adam K.; Luckasen, Mary C.

Journal Article

Objectives: Serial recall of digits is frequently used to measure short-term memory span in various listening conditions. However, the use of digits may mask the effect of low quality auditory input. Digits have high frequency and are phonologically distinct relative to one another, so they should be easy to identify even with low quality auditory input. In contrast, larger item sets reduce listener ability to strategically constrain their expectations, which should reduce identification accuracy and increase the time and/or cognitive resources needed for identification when auditory quality is low. This diminished accuracy and increased cognitive load should interfere with memory for sequences of items drawn from large sets. The goal of this work was to determine whether this predicted interaction between auditory quality and stimulus set in short-term memory exists, and if so, whether this interaction is associated with processing speed, vocabulary, or attention.
Design: We compared immediate serial recall within young adults with normal hearing across unprocessed and vocoded listening conditions for multiple stimulus sets. Stimulus sets were lists of digits (1 to 9), consonant-vowel-consonant (CVC) words (chosen from a list of 60 words), and CVC nonwords (chosen from a list of 50 nonwords). Stimuli were unprocessed or vocoded with an eight-channel noise vocoder. To support interpretation of responses, words and nonwords were selected to minimize inclusion of multiple phonemes from within a confusion cluster. We also measured receptive vocabulary (Peabody Picture Vocabulary Test PPVT-4), sustained attention (test of variables of attention TOVA), and repetition speed for individual items from each stimulus set under both listening conditions.
Results: Vocoding stimuli had no impact on serial recall of digits, but reduced memory span for words and nonwords. This reduction in memory span was attributed to an increase in phonological confusions for nonwords. However, memory span for vocoded word lists remained reduced even after accounting for common phonetic confusions, indicating that lexical status played an additional role across listening conditions. Principal components analysis found two components that explained 84% of the variance in memory span across conditions. Component one had similar load across all conditions, indicating that participants had an underlying memory capacity, which was common to all conditions. Component two was loaded by performance in the vocoded word and nonword conditions, representing the sensitivity of memory span to vocoding of these stimuli. The order in which participants completed listening conditions had a small effect on memory span that could not account for the effect of listening condition. Repetition speed was fastest for digits, slower for words, and slowest for nonwords. On average, vocoding slowed repetition speed for all stimuli, but repetition speed was not predictive of individual memory span. Vocabulary and attention showed no correlation with memory span.
Conclusions: Our results replicated previous findings that low quality auditory input can impair short-term memory, and demonstrated that this impairment is sensitive to stimulus set. Using multiple stimulus sets in degraded listening conditions can isolate memory capacity (in digit span) from impaired item identification (in word and nonword span), which may help characterize the relationship between memory and speech recognition in difficult listening conditions.

Vestibular Function Modulates the Benefit of Hearing Aids in People With Hearing Loss During Static Postural Control

01-11-2019 – Maheu, M.; Behtani, L.; Nooristani, M.; Houde, M. S.; Delcenserie, A.; Leroux, T.; Champoux, F.

Journal Article

Objectives: To evaluate the influence of auditory cues on postural sway in normal-hearing (NH) individuals, hearing-impaired individuals with vestibular impairment (HIVL), or hearing-impaired (HI) individuals without vestibular impairment.
Design: Thirty-two participants received a hearing and a vestibular evaluation (v
HIT, oVEMP, cVEMP) and then were separated in to three groups (NH, HI, HIVL). All participants had to stand on a force platform in four postural conditions (A: EO/firm, B: EC/firm, C: EO/Foam, D: EC/Foam) under two auditory conditions, with or without auditory cues.
Results: Results revealed that first, there was a significant difference between HIVL and both HI and NH groups in conditions C and D without auditory cues. Second, greater improvement for HIVL compared to NH and HI groups in condition C and D was observed with auditory cues. Finally, somatosensory reliance significantly decreased for the HIVL participants using hearing aids compared to NH and HI.
Conclusions: Our results suggest that hearing aids benefit for postural control may be modulated by vestibular function.

The Cost-Effectiveness of Bimodal Stimulation Compared to Unilateral and Bilateral Cochlear Implant Use in Adults with Bilateral Severe to Profound Deafness

01-11-2019 – Theriou, Chloi; Fielden, Claire A.; Kitterick, Pádraig T.

Journal Article

Objectives: An increasing number of severe-profoundly deaf adult unilateral cochlear implant (CI) users receive bimodal stimulation; that is, they use a conventional acoustic hearing aid (HA) in their nonimplanted ear. The combination of electric and contralateral acoustic hearing provides additional benefits to hearing and also to general health-related quality of life compared with unilateral CI use. Bilateral CI is a treatment alternative to both unilateral CI and bimodal stimulation in some healthcare systems. The objective of this study was to conduct an economic evaluation of bimodal stimulation compared with other management options for adults with bilateral severe to profound deafness.
Design: The economic evaluation took the form of a cost-utility analysis and compared bimodal stimulation (CI+HA) to two treatment alternatives: unilateral and bilateral CI. The analysis used a public healthcare system perspective based on data from the United Kingdom and the United States. Costs and health benefits were identified for both alternatives and estimated across a patient’s lifetime using Markov state transition models. Utilities were based on Health Utilities Index estimates, and health outcomes were expressed in Quality Adjusted Life Years (QALYs). The results were presented using the Incremental Cost-Effectiveness Ratio and the Net Monetary Benefit approach to determine the cost-effectiveness of bimodal stimulation. Probabilistic sensitivity analyses explored the degree of overall uncertainty using Monte Carlo simulation. Deterministic sensitivity analyses and analysis of covariance identified parameters to which the model was most sensitive; that is, whose values had a strong influence on the intervention that was determined to be most cost-effective. A value of information analysis was performed to determine the potential value to be gained from additional research on bimodal stimulation.
Results: The base case model showed that bimodal stimulation was the most cost-effective treatment option with a decision certainty of 72 and 67% in the United Kingdom and United States, respectively. Despite producing more QALYs than either unilateral CI or bimodal stimulation, bilateral CI was found not to be cost-effective because it was associated with excessive costs. Compared with unilateral CI, the increased costs of bimodal stimulation were outweighed by the gain in quality of life. Bimodal stimulation was found to cost an extra £174 per person in the United Kingdom ($937 in the US) and yielded an additional 0.114 QALYs compared with unilateral CI, resulting in an Incremental Cost-Effectiveness Ratio of £1521 per QALY gained in the United Kingdom ($8192/QALY in the United States). The most influential variable was the utility gained from the simultaneous use of both devices (CI+HA) compared with Unilateral CI. The value of further research was £4,383,922 at £20,000/QALY ($86,955,460 at $50,000/QALY in the United States).
Conclusions: This study provides evidence of the most cost-effective treatment alternative for adults with bilateral severe to profound deafness from publicly funded healthcare perspectives of the United Kingdom and United States. Bimodal stimulation was found to be more cost-effective than unilateral and bilateral CI across a wide range of willingness-to-pay thresholds. If there is scope for future research, conducting interventional designs to obtain utilities for bimodal stimulation compared with unilateral CI would reduce decision uncertainty considerably.

Round Window Membrane Motion Induced by Bone Conduction Stimulation at Different Excitation Sites: Methodology of Measurement and Data Analysis in Cadaver Study

01-11-2019 – Kwacz, Monika; Niemczyk, Kazimierz; Wysocki, Jaroslaw; Lachowska, Magdalena; Borkowski, Pawel; Malkowska, Maria; Sokolowski, Jacek

Journal Article

Objectives: The aim of this study was to investigate the following: (1) the vibration pattern of the round window (RW) membrane in human cadavers during air (AC) and bone conduction (BC) stimulation at different excitation sites; (2) the effect of the stimulation on the fluid volume displacement (VD) at the RW and compare the VD between BC and AC stimulation procedures; (3) the effectiveness of cochlear stimulation by the bone implant at different excitation sites.
Design: The RW membrane vibrations were measured by using a commercial scanning laser Doppler vibrometer. The RW vibration amplitude was recorded at 69 measurement points evenly distributed in the measurement field covering the entire surface of the RW membrane and a part of the surrounding bony surface. RW vibration was induced first with AC and then with BC stimulation through an implant positioned at two sites. The first site was on the skull surface at the squamous part of the temporal bone (implant no. 1), a place typical for bone-anchored hearing aids. The second site was close to the cochlea at the bone forming the ampulla of the lateral semicircular canal (implant no. 2). The displacement amplitude (d
P) of the point P on the promontory was determined and used to calculate the relative displacement (dr
RW) of points on the RW membrane, dr
RW = d
RW − d
P. VD parameter was used to analyze the effectiveness of cochlear stimulation by the bone implant screwed at different excitation sites.
Results: RW membrane displacement amplitude of the central part of the RW was similar for AC and BC implant no. 1 stimulation, and for BC implant no. 2 much larger for frequency range >1 k
Hz. BC implant no. 2 causes a larger displacement amplitude of peripheral parts of the RW and the promontory than AC and BC implant no. 1, and BC implant no. 1 causes larger than AC stimulation. The effect of BC stimulation exceeds that of AC with identical intensity, and that the closer BC stimulation to the otic capsule, the more effective this stimulation is. A significant decrease in the value of VD at the RW is observed for frequencies >2 k
Hz for both AC and BC stimulation with BC at both locations of the titanium implant placement. For frequencies >1 k
Hz, BC implant no. 2 leads to a significantly larger VD at the RW compared to BC implant no. 1. Thus, the closer to the otic capsule the BC stimulation is located, the more effective it is.
Conclusions: Experimental conditions allow for an effective acoustic stimulation of the inner ear by an implant screwed to the osseous otic capsule. The mechanical effect of BC stimulation with a titanium implant placed in the bone of the ampulla of the lateral semicircular canal significantly exceeds the effect of an identical stimulation with an implant placed in the temporal squama at a conventional site for an implant anchored in the bone. The developed research method requires the implementation on a larger number of temporal bones in order to obtain data concerning interindividual variability of the observed mechanical phenomena.

Auditory Training for Adult Cochlear Implant Users: A Survey and Cost Analysis Study

01-11-2019 – Reis, Mariana; Boisvert, Isabelle; Beedell, Emma; Mumford, Virginia

Journal Article

Objectives: The aims of this study were as follows: (a) to describe audiologists’ practices toward auditory training (AT) for adult cochlear implant (CI) users with a postlingual hearing loss; and (b) to assess the cost of different AT methods for clients and service providers in comparison with no AT delivery.
Design: A survey was distributed to approximately 230 Australian CI audiologists to investigate the range, magnitude, and rationale of AT practices adopted as part of rehabilitation services with adult CI users. The cost of these different AT practices was then estimated from the perspectives of both clients and service providers, and compared against no AT delivery.
Results: Seventy-eight audiologists responded to at least one section of the survey (16% to 33% response rate), of which 85.5% reported that they viewed AT as a necessary component of rehabilitation. Home-based and face-to-face were the methods most frequently adopted to deliver AT. Methods used during training, such as stimuli type, feedback, and encouragement for training adherence, varied across respondents. The cost analysis indicated that home-based training resulted in the lowest program costs, whereas face-to-face AT (when delivered independently from routine appointments) was the method with highest cost for clients and service providers.
Conclusions: The type of AT, recommended frequency of sessions, and overall duration of programs varied widely across respondents. Costs incurred by clients depended mainly on whether the AT was home-based or clinician-led (i.e., face-to-face, group-based), program fees, and travel arrangements made by clients, as well as clinicians’ wages and the method chosen to deliver AT.

Test/Retest Variability of the eCAP Threshold in Advanced Bionics Cochlear Implant Users

01-11-2019 – Stronks, H. Christiaan; Biesheuvel, Jan Dirk; de Vos, Johan J.; Boot, Martijn S.; Briaire, Jeroen J.; Frijns, Johan H. M.

Journal Article

Objective: The reliability of the electrically evoked compound action potential (e
CAP) threshold depends on its precision and accuracy. The precision of the e
CAP threshold reflects its variability, while the accuracy of the threshold shows how close it is to the actual value. The objective of this study was to determine the test/retest variability of the e
CAP threshold in Advanced Bionics cochlear implant users, which has never been reported before. We hypothesized that the test/retest variability is dependent on the presence of random noise in the recorded e
CAP waveforms. If this holds true, the recorded error should be reduced by approximately the square-root of the number of averages. As secondary objectives, we assessed the effects of the slope of the amplitude growth function (AGF), cochlear location, and e
CAP threshold on e
CAP threshold precision. We hypothesized that steeper slopes should result in better precision of the linearly extrapolated e
CAP threshold. As other studies have shown that apical regions have steeper slopes and larger e
CAPs, we recorded e
CAPs in three different cochlear locations. The difference of the precision between two commonly applied stimulus-artifact reduction paradigms on e
CAP threshold precision was compared, namely averaging of alternating stimulus polarities (AP averaging) and forward masking (FM). FM requires the addition of more waveforms than AP averaging, and hence we expected FM to have lower precision than AP.
Design: This was an unmasked, descriptive, and observational study with a cross-over (repeated measures) design that included 13 subjects. We recorded e
CAPs on three electrode contacts: in the base, middle, and apex of the cochlea at 10 stimulus intensities. Per stimulus level, 256 e
CAP waveforms were recorded. e
CAP thresholds were determined by constructing AGFs and linear extrapolation to zero-amplitude. The precision of the e
CAP threshold was calculated as the SD using a Monte Carlo simulation, as a function of the number of waveform averages.
Results: The SD of the e
CAP threshold was reduced by approximately the square root of two when the number of averages in the e
CAP waveforms was doubled. The precision was significantly better when the slope of the AGF was steeper and was more favorable in the cochlear base than in the apex. Precision was better when AP averaging was used. Absolute e
CAP threshold did not significantly affect precision. At the default number of 32 waveform averages in the Advanced Bionics system, we report a median SD of the e
CAP threshold of 2 to 3 μA, with a range of 1 to 11 μA across the cochlea. Previous studies have shown that the total error, based on the 95% confidence bounds of the linear extrapolation, can be as high as −260 to +120 μA.
Conclusions: The median variability in the e
CAP threshold proved to be small compared with the total variability introduced by the linear extrapolation method. Yet there was substantial intersubject variability. Therefore, we recommend monitoring the SD during e
CAP recording to facilitate informed decisions when to terminate waveform collection. From a precision perspective, AP averaging is preferable over FM as it has better precision, while fewer recordings are needed, making it the more time-efficient method of the two.

The Fear of Tinnitus Questionnaire: Toward a Reliable and Valid Means of Assessing Fear in Adults with Tinnitus

01-11-2019 – Fuller, Thomas E.; Cima, Rilana F. F.; Van den Bussche, Eva; Vlaeyen, Johan W. S.

Journal Article

Objectives: The purpose of this study was to assess the factor structure, reliability, and validity of the Fear of Tinnitus Questionnaire (FTQ); a brief self-report measure of people’s fears about potential cognitive, emotional, behavioral, and social consequences of living with tinnitus.
Design: Five hundred eighty-eight Dutch-speaking adults with tinnitus completed an online battery of questionnaires measuring tinnitus-related distress, fear, catastrophizing, and quality of life. The sample was randomly split into two to perform exploratory and Bayesian confirmatory factor analyses. A subsample of participants (n = 144) completed the battery of questionnaires a second time after a 2-week interval to calculate test-retest reliability and conduct a Bland-Altman analysis. Convergent and concurrent validity of the FTQ was assessed with the complete data set and measures of tinnitus-related distress as the outcome.
Results: Exploratory factor analyses indicated that single- and three-factor FTQ models were both valid solutions. Posterior predictive p values for the Bayesian confirmatory factor analyses ranged between 0.51 and 0.53 indicating that the respective models were an excellent fit for the data. The FTQ showed excellent test-retest reliability (average value intraclass correlation coefficient (ICC) = 0.92; 95% confidence interval, 0.89–0.95) and in the Bland-Altman analysis, satisfactory agreement between participants’ scores after a 2-week interval. Furthermore, the FTQ demonstrated good internal reliability (α = 0.83, 95% confidence interval, 0.81–0.85) and added statistically significant amounts of variance to models predicting tinnitus-related distress and interference in daily life.
Conclusions: The FTQ has good psychometric properties and can be used to assess people’s fear of tinnitus in research or clinical settings. Further work to establish the reliability and validity should be conducted and include an examination of a version of the FTQ that uses Likert-type response scales which might offer improved sensitivity.

Validating a Quick Spectral Modulation Detection Task

01-11-2019 – Landsberger, David M.; Dwyer, Robert T.; Stupak, Natalia; Gifford, René H.

Journal Article

Objectives: The Quick Spectral Modulation Detection (QSMD) test provides a quick and clinically implementable spectral resolution estimate for cochlear implant (CI) users. However, the original QSMD software (QSMD(My
Sound)) has technical and usability limitations that prevent widespread distribution and implementation. In this article, we introduce a new software package Easy
QSMD, which is freely available software with the goal of both simplifying and standardizing spectral resolution measurements.
Design: QSMD was measured for 20 CI users using both software packages.
Results: No differences between the two software packages were detected, and based on the 95% confidence interval of the difference between tests, the difference between the tests is expected to be <2% points. The average test duration was under 4 minutes.
Conclusions: Easy
QSMD is considered functionally equivalent to QSMD(My
Sound) providing a clinically feasible and quick estimate of spectral resolution for CI users.

Resource Review

01-11-2019 – Voss, Susan E.

Journal Article

No abstract available