Πέμπτη 8 Αυγούστου 2019

A Comparison of Intracochlear Pressures During Ipsilateral and Contralateral Stimulation With a Bone Conduction Implant
Objectives: To compare contralateral to ipsilateral stimulation with percutaneous and transcutaneous bone conduction implants. Background: Bone conduction implants (BCIs) effectively treat conductive and mixed hearing losses. In some cases, such as in single-sided deafness, the BCI is implanted contralateral to the remaining healthy ear in an attempt to restore some of the benefits provided by binaural hearing. While the benefit of contralateral stimulation has been shown in at least some patients, it is not clear what cues or mechanisms contribute to this function. Previous studies have investigated the motion of the ossicular chain, skull, and round window in response to bone vibration. Here, we extend those reports by reporting simultaneous measurements of cochlear promontory velocity and intracochlear pressures during bone conduction stimulation with two common BCI attachments, and directly compare ipsilateral to contralateral stimulation. Methods: Fresh–frozen whole human heads were prepared bilaterally with mastoidectomies. Intracochlear pressure (PIC) in the scala vestibuli (PSV) and tympani (PST) was measured with fiber optic pressure probes concurrently with cochlear promontory velocity (VProm) via laser Doppler vibrometry during stimulation provided with a closed-field loudspeaker or a BCI. Stimuli were pure tones between 120 and 10,240 Hz, and response magnitudes and phases for PIC and VProm were measured for air and bone conducted sound presentation. Results: Contralateral stimulation produced lower response magnitudes and longer delays than ipsilateral in all measures, particularly for high-frequency stimulation. Contralateral response magnitudes were lower than ipsilateral response magnitudes by up to 10 to 15 dB above ~2 kHz for a skin-penetrating abutment, which increased to 25 to 30 dB and extended to lower frequencies when applied with a transcutaneous (skin drive) attachment. Conclusions: Transcranial attenuation and delay suggest that ipsilateral stimulation will be dominant for frequencies over ~1 kHz, and that complex phase interactions will occur during bilateral or bimodal stimulation. These effects indicate a mechanism by which bilateral users could gain some bilateral advantage. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and text of this article on the journal’s Web site (www.ear-hearing.com). ACKNOWLEDGMENTS: J.K.M., H.A.J., D.J.T., S.P.C., and N.T.G. designed and performed the experiments; H.A.J., D.J.T., and S.P.C. reviewed data and provided interpretive analysis; J.K.M., R.M.B.H., S.P.C., and N.T.G. analyzed data and wrote the paper. All authors discussed the results and implications and commented on the manuscript at all stages. This work was supported by AAO-HNSF Resident Research Grant from The Oticon Foundation (to J. K. M.) and NIH/NIDCD 1T32-DC012280 (to R. M. B. H. and N. T. G.). We appreciate the assistance of Dr. Michael Hall in constructing some of the custom experimental equipment (supported by National Institutes of Health grant P30 NS041854). S.P.C. is a consultant for Cochlear Corporation. The other authors have no conflicts of interest to disclose. Received January 8, 2018; accepted May 15, 2019. Address for correspondence: Nathaniel T. Greene, Department of Otolaryngology, University of Colorado School of Medicine, 12631 E. 17th Avenue, B205, Aurora, CO 80045, USA. E-mail: nathaniel.greene@ucdenver.edu Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.
10-Year Follow-Up Results of The Netherlands Longitudinal Study on Hearing: Trends of Longitudinal Change in Speech Recognition in Noise
Objectives: Previous findings of longitudinal cohort studies indicate that acceleration in age-related hearing decline may occur. Five-year follow-up data of the Netherlands Longitudinal Study on Hearing (NL-SH) showed that around the age of 50 years, the decline in speech recognition in noise accelerates compared with the change in hearing in younger participants. Other longitudinal studies confirm an accelerated loss in speech recognition in noise but mostly use older age groups as a reference. In the present study, we determined the change in speech recognition in noise over a period of 10 years in participants aged 18 to 70 years at baseline. We additionally investigated the effects of age, sex, educational level, history of tobacco smoking, and alcohol use on the decline of speech recognition in noise. Design: Baseline (T0), 5-year (T1), and 10-year (T2) follow-up data of the NL-SH collected until May 2017 were included. The NL-SH is a web-based prospective cohort study which started in 2006. Central to the NL-SH is the National Hearing test (NHT) which was administered to the participants at all three measurement rounds. The NHT uses three-digit sequences which are presented in a background of stationary noise. The listener is asked to enter the digits using the computer keyboard. The outcome of the NHT is the speech reception threshold in noise (SRT) (i.e., the signal to noise ratio where a listener recognizes 50% of the digit triplets correctly). In addition to the NHT, participants completed online questionnaires on demographic, lifestyle, and health-related characteristics at T0, T1, and T2. A linear mixed model was used for the analysis of longitudinal changes in SRT. Results: Data of 1349 participants were included. At the start of the study, the mean age of the participants was 45 years (SD 13 years) and 61% of the participants were categorized as having good hearing ability in noise. SRTs significantly increased (worsened) over 10 years (p < 0.001). After adjustment for age, sex, and a history of tobacco smoking, the mean decline over 10 years was 0.89 dB signal to noise ratio. The decline in speech recognition in noise was significantly larger in groups aged 51 to 60 and 61 to 70 years compared with younger age groups (18 to 30, 31 to 40, and 41 to 50 years) (p < 0.001). Speech recognition in noise in participants with a history of smoking declined significantly faster during the 10-year follow-up interval (p = 0.003). Sex, educational level, and alcohol use did not appear to influence the decline of speech recognition in noise. Conclusions: This study indicated that speech recognition in noise declines significantly over a 10-year follow-up period in adults aged 18 to 70 years at baseline. It is the first longitudinal study with a 10-year follow-up to reveal that the increased rate of decline in speech recognition ability in noise already starts at the age of 50 years. Having a history of tobacco smoking increases the decline of speech recognition in noise. Hearing health care professionals should be aware of an accelerated decline of speech recognition in noise in adults aged 50 years and over. ACKNOWLEDGMENTS: The authors thank the participants on the Netherlands Longitudinal Study on Hearing (NL-SH). The authors also thank the assistance of Celina Henke in managing the database. The first measurement round of the Netherlands Longitudinal Study on Hearing (NL-SH) (2006–2010) was financially supported by the Heinsius Houbolt Foundation, The Netherlands. Sonova AG, Switzerland supported the data collection of the second measurement round (since 2011). Funding for data collection of the third measurement round (since 2016) came from the EMGO Institute for Health and Care Research, The Netherlands, and Sonova AG, Switzerland. T.P.M.G., M.S., P.M., U.L., C.S., and S.E.K. were involved in formulating the research questions and in designing the study. T.P.M.G. performed the analysis and M.S. and B.I.L.-W. verified the analytical methods. T.P.M.G. took the lead in writing the article. All authors provided critical feedback and helped shape the research, analysis, and article. Received June 28, 2018; accepted June 19, 2019. The authors have no conflicts of interest to disclose. Address for correspondence: Thadé P. M. Goderie, Department of Otolaryngology/Head and Neck Surgery, Section Ear and Hearing, Amsterdam University Medical Center, P.O. Box 7057, 1007 MB, Amsterdam, The Netherlands. E-mail: t.goderie@vumc.nl This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.
The Role of Lexical Tone Information in the Recognition of Mandarin Sentences in Listeners With Hearing Aids
Objectives: Lexical tone information provides redundant cues for the recognition of Mandarin sentences in listeners with normal hearing in quiet conditions. The contribution of lexical tones to Mandarin sentence recognition in listeners with hearing aids (HAs) is unclear. This study aimed to remove lexical tone information and examine the effects on Mandarin sentence intelligibility in HA users. The second objective was to investigate the contribution of cognitive abilities (i.e., general cognitive ability, working memory, and attention) on Mandarin sentence perception when the presentation of lexical tone information was mismatched. Design: A text-to-speech synthesis engine was used to manipulate Mandarin sentences into three test conditions: (1) a Normal Tone test condition, where no alterations were made to lexical tones within sentences; (2) a Flat Tone test condition, where lexical tones were all changed into tone 1 (i.e., the flat tone); and (3) a Random Tone test condition, where each word in test sentences was randomly assigned one of four Mandarin lexical tones. The manipulated sentence signals were presented to 32 listeners with HAs in both quiet and noisy environments at an 8 dB signal to noise ratio. Results: Speech intelligibility was reduced significantly (by approximately 40 percentage points) in the presence of mismatched lexical tone information in both quiet and noise. The difficulty in correctly identifying sentences with mismatched lexical tones among adults with hearing loss was significantly greater than that of adults with normal hearing. Cognitive function was not significantly related to a decline in speech recognition scores. Conclusions: Contextual and other phonemic cues (i.e., consonants and vowels) are inadequate for HA users to perceive sentences with mismatched lexical tone contours in quiet or noise. Also, HA users with better cognitive function could not compensate for the loss of lexical tone information. These results highlight the importance of accurately representing lexical tone information for Mandarin speakers using HAs. ACKNOWLEDGMENTS: Y.C., L.L.N.W, J.Q., V.K., and S.C.V. designed experiments. Y.C. analyzed data and wrote the article; L.L.N.W. provided critical revision. F.C. created the test materials. All authors discussed the results and implications and commented on the article at all stages. The study described in this article was partially supported by the Research Seed Fund 2018/2019 of the Department of Special Education and Counselling at the Education University of Hong Kong and by Phonak China. The authors have no conflicts of interest to disclose. Received September 24, 2018; accepted June 6, 2019. Address for correspondence: Yuan Chen, Department of Special Education and Counselling, The Education University of Education, Hong Kong SAR, China. E-mail: cheny@eduhk.hk Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.
Age Effects on Cochlear Reflectance in Adults
Objectives: Cochlear reflectance (CR) is the cochlear contribution to ear-canal reflectance. CR is a type of otoacoustic emission that is calculated as a transfer function between forward pressure and reflected pressure. The purpose of this study was to assess effects of age on CR in adults and interactions among age, sex, and hearing loss. Design: Data were collected from 60 adults selected for their age (e.g., 20–29, 30–39, 40–49, 50–59, 60–69, 70–79 years) and normal middle ear status. A wideband noise stimulus presented at three stimulus levels (30, 40, 50 dB SPL) was used to elicit CR. Half-octave bands of CR signal magnitude (CRM), CR noise, and the CR signal-to-noise ratio (CR-SNR) were extracted from the wideband CR response. Regression analyses were conducted to assess interactions among CR, age, sex, and pure-tone thresholds at closely matched frequency bands across stimulus levels. Results: Although increased age was generally associated with lower CRM and CR-SNR at some band frequencies and stimulus levels, no significant effects of age remained after controlling for effects of pure-tone thresholds. Increases in pure-tone thresholds were associated with lower CRM and CR-SNR at most frequency bands and stimulus levels. Effects of hearing sensitivity were significant at some frequencies and levels after controlling for age and sex. Conclusions: When effects of age were controlled, adults with better hearing had significantly larger CRM and CR-SNR than those with poorer hearing. In contrast, when effects of hearing were controlled, no significant effects of age on CRM and CR-SNR remained. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and text of this article on the journal’s Web site (www.ear-hearing.com). ACKNOWLEDGMENTS: All authors contributed equally to this work. S. E. F. collected data and wrote the main paper; K. I. V. performed the modeling and statistical analysis and provided the Supplementary Materials (Supplemental Digital Content 1 and 2, http://links.lww.com/EANDH/A556 and http://links.lww.com/EANDH/A557); J. G. K. contributed to experiment design and revisions; J. R. D., S. T. N., and D. M. R. reviewed data and provided interpretive analysis and critical revisions. All authors discussed the results and implications and commented on the manuscript at all stages. We are grateful to Jayne Ahlstrom, Michael Gorga, Natalie Lenzen, and Matthew Waid for their contributions to study development, calibration, and data collection. This research was supported by grants R01 DC8318, R01 DC016348, P30 DC4662, R01 DC000184, and P50 DC000422 from the National Institute of Health/National Institute on Deafness and Other Communication Disorders The authors have no conflicts of interest to disclose. Received December 12, 2018; accepted May 31, 2019. Address for correspondence: Sara E. Fultz, Center for Hearing Research, Boys Town National Research Hospital, 555 N 30th St. Omaha, Nebraska 68131, USA. E-mail: sara.fultz@boystown.org Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.
Health Literacy and Self-Reported Hearing Aid Use in the Health and Retirement Study
Objectives: Understanding the determinants of hearing aid use is important to improve the provision of hearing healthcare. Prior research has indicated that materials in the clinic and online, as well as audiologists’ language during appointments, require a higher literacy level than most patients possess. We hypothesized that low health literacy is a barrier to entry in hearing healthcare, and therefore that health literacy would be positively correlated with the probability of hearing aid use. Design: We performed retrospective analyses of the Health and Retirement Study, a longitudinal survey of American adults of retirement age. Objective health literacy was measured in different but overlapping subsamples using subsets of the Test of Functional Health Literacy in Adults and the Rapid Estimate of Adult Literacy in Medicine (n = 1240, n = 1586, and n = 2412). Subjective health literacy was assessed using a single-question screener in a larger sample (n = 8362). Separate discrete time models including common covariates of hearing aid use were constructed for each subsample. Results: Objective health literacy measures did not correlate significantly with hearing aid use when age, gender, race/ethnicity, self-assessed hearing ability, and net income were included in the models. Subjective health literacy did correlate significantly with hearing aid use in the complete model, with lower subjective health literacy correlated with lower odds of reporting hearing aid use. Conclusions: Taken at face value, the results provide mixed evidence for a link between health literacy and hearing aid use. The results from the analysis of the largest sample, using the subjective health literacy measure, were consistent with the hypothesis that low health literacy is a barrier to hearing aid use. However, this was not supported by the analysis of the objective health literacy measures in these samples. Further research using full health literacy measurement tools and capturing other relevant variables would offer clarification on this conflict. The literacy level of clinical materials and conversation is a modifiable potential factor in hearing aid uptake, so further clinical and research consideration is warranted. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and text of this article on the journal’s Web site (www.ear-hearing.com). ACKNOWLEDGMENTS: The Health and Retirement Study is supported by NIA U01AG009740 and the Social Security Administration. N.K., Z.M.S., and S.D. contributed to the analysis design. N.K. conducted the analysis. N.K. and Z.M.S. drafted the paper. All authors reviewed, edited, and approved the final paper. The authors have no conflicts of interest to disclose. Received August 28, 2018; accepted May 29, 2019. Address for correspondence: Niall Andre Munson Klyn, The Richard and Roxelyn Pepper Department of Communication Sciences and Disorders, Northwestern University, 2240 Campus Drive, Evanston, IL 60208, USA. E-mail: niall.klyn@northwestern.edu Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.
A Cross-Sectional Study of the Prevalence and Factors Associated With Tinnitus and/or Hyperacusis in Children
Objectives: The aim of this study was to determine the prevalence of tinnitus and/or hyperacusis in Danish children aged 10 to 16 years, and to assess associations between tinnitus or hyperacusis and other relevant factors. Design: A cross-sectional study based on a previously established child cohort. A total of 501 children were enrolled in the project. The study was performed in eight mainstream schools and data were collected during an 8-week period from October 27, 2014 to December 16, 2014. Results: Using broad tinnitus research questions, the prevalence of any tinnitus was 66.9%; of noise-induced tinnitus (NIT) was 35.7%; and of spontaneous tinnitus (ST) was 53.7%. Bothersome tinnitus was reported by 34.6% of the children with any tinnitus, 23.2% of the whole population. Few children were severely bothered (2.4%, 1.6%, respectively). It was significantly more common for children with NIT to report tinnitus episodes lasting for minutes or longer than for children with ST (p = 0.01). Girls were more likely than boys to be bothered by tinnitus [Odds ratio (OR) = 2.96; 95% confidence interval (CI) 1.34 to 6.51; p = 0.01]. 14.6% of the children reported hyperacusis, and 72.6% of those reporting hyperacusis were bothered by it, 10.6% of the whole population. The odds of having hyperacusis were 4.73 (1.57, 14.21) times higher among those with ST compared with those without ST. Furthermore, hyperacusis was associated with sound avoidance behaviors such as experience of sound-induced pain in the ear (OR = 2.95, 95% CI 1.65 to 5.27; p < 0.001), withdrawal from places or activities (OR = 3.33; 95% CI 1.44 to 7.69; p = 0.01), or concerns about sound could damage the hearing (OR = 1.85, 95% CI 1.06 to 3.31; p = 0.03). Conclusions: Tinnitus and hyperacusis are common in children but prevalence is dependent on tinnitus definitions. Only a few children are severely bothered by tinnitus. In the case of hyperacusis, children may exhibit sound avoidance behavior. ACKNOWLEDGMENTS: First, we thank all the children and families participating in this study. We are also extremely grateful for the accept from the ALSPAC-study for collaboration in terms of providing their questionnaire and study protocol for us to use and their additional help. We also thank The Municipality of Svendborg and the Svendborg Project for including us in their project. SDE College Odense kindly participated with final-year students that provided all hearing measurements. A special thanks to technician Arne Hutflesz for his support and ongoing technical assistant. Rachel Humphriss and Amanda Hall were generous in sharing the protocol and definitions used in Humphriss et al. (2016). The present publication is the work of the authors, and Susanne Nemholt will serve as guarantor for the contents of this article. This study is part of the Ph.D. project Tinnitus and Hyperacusis Among Children and Adolescents in Denmark (THACAD), which has been funded by The Capital Region of Denmark, The University of Southern Denmark and The Danish Association of the Hard of Hearing. This particular study was additional funded by Oticon Fonden and GN Store Nord Fondet. This report is independent research, and David Baguley’s involvement is funded by the National Institute for Health Research. The views expressed in this publication are those of the authors, and not necessarily those of the NHS, the National Institute for Health Research, nor the UK Department of Health. The authors have no conflicts of interest to disclose. Received August 5, 2016; accepted May 20, 2019. Address for correspondence: Susanne Nemholt, Syddansk Universitet, Campusvej 55, DK-5230 Odense, Denmark. E-mail: snemholt@health.sdu.dk This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.
Masking Release for Speech-in-Speech Recognition Due to a Target/Masker Sex Mismatch in Children With Hearing Loss
Objectives: The goal of the present study was to compare the extent to which children with hearing loss and children with normal hearing benefit from mismatches in target/masker sex in the context of speech-in-speech recognition. It was hypothesized that children with hearing loss experience a smaller target/masker sex mismatch benefit relative to children with normal hearing due to impairments in peripheral encoding, variable access to high-quality auditory input, or both. Design: Eighteen school-age children with sensorineural hearing loss (7 to 15 years) and 18 age-matched children with normal hearing participated in this study. Children with hearing loss were bilateral hearing aid users. Severity of hearing loss ranged from mild to severe across participants, but most had mild to moderate hearing loss. Speech recognition thresholds for disyllabic words presented in a two-talker speech masker were estimated in the sound field using an adaptive, forced-choice procedure with a picture-pointing response. Participants were tested in each of four conditions: (1) male target speech/two-male-talker masker; (2) male target speech/two-female-talker masker; (3) female target speech/two-female-talker masker; and (4) female target speech/two-male-talker masker. Children with hearing loss were tested wearing their personal hearing aids at user settings. Results: Both groups of children showed a sex-mismatch benefit, requiring a more advantageous signal to noise ratio when the target and masker were matched in sex than when they were mismatched. However, the magnitude of sex-mismatch benefit was significantly reduced for children with hearing loss relative to age-matched children with normal hearing. There was no effect of child age on the magnitude of sex-mismatch benefit. The sex-mismatch benefit was larger for male target speech than for female target speech. For children with hearing loss, the magnitude of sex-mismatch benefit was not associated with degree of hearing loss or aided audibility. Conclusions: The findings from the present study indicate that children with sensorineural hearing loss are able to capitalize on acoustic differences between speech produced by male and female talkers when asked to recognize target words in a competing speech masker. However, children with hearing loss experienced a smaller benefit relative to their peers with normal hearing. No association between the sex-mismatch benefit and measures of unaided thresholds or aided audibility were observed for children with hearing loss, suggesting that reduced peripheral encoding is not the only factor responsible for the smaller sex-mismatch benefit relative to children with normal hearing. ACKNOWLEDGMENTS: This research was supported by the National Institute on Deafness and Other Communication Disorders of the National Institutes of Health under award number R01 DC011038 (L. J. L.) and subject recruitment was supported by the National Institute of General Medical Sciences of the National Institutes of Health under award number P20GM109023. The authors have no conflicts of interest to disclose. Received June 28, 2018; accepted May 1, 2019. Address for correspondence: Lori J. Leibold, Center for Hearing Research, Boys Town National Research Hospital, 555 North 30th Street, Omaha, NE 68131, USA. E-mail: lori.leibold@boystown.org Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.
Barriers and Facilitators to Cochlear Implant Uptake in Australia and the United Kingdom
Objectives: Hearing loss (HL) affects a significant proportion of adults aged >50 years by impairing communication and social connectedness and, due to its high prevalence, is a growing global concern. Cochlear implants (CIs) are effective devices for many people with severe or greater sensorineural HL who experience limited benefits from hearing aids. Despite this, uptake rates globally are low among adults. This multimethod, multicountry qualitative study aimed to investigate the barriers and facilitators to CI uptake among adults aged ≥50 years. Design: Adult CI and hearing aid users with postlingual severe or greater sensorineural HL, general practitioners, and audiologists were recruited in Australia using purposive sampling, and a comparative sample of audiologists was recruited in England and Wales in the United Kingdom. Participants were interviewed individually, or in a focus group, completed a demographic questionnaire and a qualitative survey. Data were analyzed using thematic analysis. Results: A total of 143 data capture events were collected from 55 participants. The main barriers to CI uptake related to patients’ concerns about surgery and loss of residual hearing. Limited knowledge of CIs, eligibility criteria, and referral processes acted as barriers to CIs assessment referrals by healthcare professionals. Facilitators for CI uptake included patients’ desire for improved communication and social engagement, and increased healthcare professional knowledge and awareness of CIs. Conclusions: There are numerous complex barriers and facilitators to CI uptake. Knowledge of these can inform the development of targeted strategies to increase CI referral and surgery for potential beneficiaries. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and text of this article on the journal’s Web site (www.ear-hearing.com). ACKNOWLEDGMENTS: We thank all of the participants who took part in this study, and the Macquarie University-Cochlear Ltd Partnership (MQ-Cochlear), for funding this research. M.R.B. designed the study, performed the data collection, analyzed and interpreted the data and wrote the paper; C.M.M., I.B., and F.R. designed the study, provided guidance for data collection, interpretive analysis, and commented on the manuscript at all stages. S.H. designed the study and performed the data collection in the United Kingdom, provided interpretive analysis and commented on the manuscript at all stages; A.Y.S.L. and J.B. designed the study and commented on the manuscript at all stages. All authors discussed the results and implications and commented on the manuscript at all stages. All authors provided final approval of the manuscript submitted. The authors would like to disclose that another manuscript has been prepared reporting results from this study, not reported in this manuscript, which will be submitted to another journal. The authors received financial support for the study from the Macquarie University-Cochlear Ltd Partnership (MQ-Cochlear). Authors had full control over the study design, conduct, and analysis. The authors have no conflicts of interest to disclose. Received September 13, 2018; accepted May 27, 2019. Address for correspondence: Mia Bierbaum, Australian Institute of Health Innovation, Macquarie University, Level 6, 75 Talavera Road, Macquarie University, NSW, 2109. E-mail: Mia.bierbaum@mq.edu.au This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.
Effects of Simulated and Profound Unilateral Sensorineural Hearing Loss on Recognition of Speech in Competing Speech
Objectives: Unilateral hearing loss (UHL) is a condition as common as bilateral hearing loss in adults. Because of the unilaterally reduced audibility associated with UHL, binaural processing of sounds may be disrupted. As a consequence, daily tasks such as listening to speech in a background of spatially distinct competing sounds may be challenging. A growing body of subjective and objective data suggests that spatial hearing is negatively affected by UHL. However, the type and degree of UHL vary considerably in previous studies. The aim here was to determine the effect of a profound sensorineural UHL, and of a simulated UHL, on recognition of speech in competing speech, and the binaural and monaural contributions to spatial release from masking, in a demanding multisource listening environment. Design: Nine subjects (25 to 61 years) with profound sensorineural UHL [mean pure-tone average (PTA) across 0.5, 1, 2, and 4 kHz = 105 dB HL] and normal contralateral hearing (mean PTA = 7.2 dB HL) were included based on the criterion that the target and competing speech were inaudible in the ear with hearing loss. Thirteen subjects with normal hearing (19 to 60 years; mean left PTA = 4.1 dB HL; mean right PTA = 5.5 dB HL) contributed data in normal and simulated “mild-to-moderate” UHL conditions (PTA = 38.6 dB HL). The main outcome measure was the threshold for 40% correct speech recognition in colocated (0°) and spatially and symmetrically separated (±30° and ±150°) competing speech conditions. Spatial release from masking was quantified as the threshold difference between colocated and separated conditions. Results: Thresholds in profound UHL were higher (worse) than normal hearing in separated and colocated conditions, and comparable to simulated UHL. Monaural spatial release from masking, that is, the spatial release achieved by subjects with profound UHL, was significantly different from zero and 49% of the magnitude of the spatial release from masking achieved by subjects with normal hearing. There were subjects with profound UHL who showed negative spatial release, whereas subjects with normal hearing consistently showed positive spatial release from masking in the normal condition. The simulated UHL had a larger effect on the speech recognition threshold for separated than for colocated conditions, resulting in decreased spatial release from masking. The difference in spatial release between normal-hearing and simulated UHL conditions increased with age. Conclusions: The results demonstrate that while recognition of speech in colocated and separated competing speech is impaired for profound sensorineural UHL, spatial release from masking may be possible when competing speech is symmetrically distributed around the listener. A “mild-to-moderate” simulated UHL decreases spatial release from masking compared with normal-hearing conditions and interacts with age, indicating that small amounts of residual hearing in the UHL ear may be more beneficial for separated than for colocated interferer conditions for young listeners. ACKNOWLEDGMENTS: The authors are grateful to Maria Drott, Malin Apler, Jenny Andersson, Linda Persson, and Ann-Charlotte Persson for assistance in measurements; Per-Olof Larsson for technical assistance; and the subjects for participating. This work was supported by the Hasselblad Foundation. Part of this work was previously presented as an oral article at the 6th International Congress on Bone Conduction Hearing and Related Technologies, Nijmegen, The Netherlands, May 17–20, 2017. The authors have no conflicts of interest to declare. Received March 27, 2018; accepted May 28, 2019. Address for correspondence: Filip Asp, Department of ENT, Section of Hearing Implants, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden. E-mail: filip.asp@ki.se This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.
AVATAR Assesses Speech Understanding and Multitask Costs in Ecologically Relevant Listening Situations
Objectives: There is a high need among clinicians and researchers for an ecologically valid measure of auditory functioning and listening effort. Therefore, we developed AVATAR: an “Audiovisual True-to-life Assessment of Auditory Rehabilitation” which takes important characteristics of real-life listening situations into account, such as multimodal speech presentation, spatial separation of sound sources and multitasking. As such, AVATAR aims to assess both auditory functioning and the amount of allocated processing resources during listening in a realistic yet controllable way. In the present study, we evaluated AVATAR and investigated whether speech understanding in noise and multitask costs during realistic listening environments changed with increasing task complexity. Design: Thirty-five young normal-hearing participants performed different task combinations of an auditory-visual speech-in-noise task and three secondary tasks on both auditory localization and visual short-term memory in a simulated restaurant environment. Tasks were combined in increasing complexity and multitask costs on the secondary tasks were investigated as an estimate of the amount of cognitive resources allocated during listening and multitasking. In addition to behavioral measures of auditory functioning and effort, working memory capacity and self-reported hearing difficulties were established using a reading span test and a questionnaire on daily hearing abilities. Results: Whereas performance on the speech-in-noise task was not affected by task complexity, multitask costs on one of the secondary tasks became significantly larger with increasing task complexity. Working memory capacity correlated significantly with multitask costs, but no association was observed between behavioral outcome measures and self-reported hearing abilities or effort. Conclusions: AVATAR proved to be a promising model to assess speech intelligibility and auditory localization abilities and to gauge the amount of processing resources during effortful listening in ecologically relevant multitasking situations by means of multitask costs. In contrast with current clinical measures of auditory functioning, results showed that listening and multitasking in challenging listening environments can require a considerable amount of processing resources, even for young normal-hearing adults. Furthermore, the allocation of resources increased in more demanding listening situations. These findings open avenues for a more realistic assessment of auditory functioning and individually tuned auditory rehabilitation for individuals of different age and hearing profiles. ACKNOWLEDGMENTS: The authors thank professor Ralf Krampe for sharing interesting insights and Alexander Dudek for his technical support. This research project was supported with grants from the Oticon Foundation (Oticon Fonden), the Research Council of KU Leuven through project 0T/12/98 and a TBM-FWO Grant from the Research Foundation-Flanders (T002216N). Received August 4, 2018; accepted June 10, 2019. Address for correspondence: Annelies Devesse, KU Leuven Department of Neurosciences, ExpORL Herestraat 49 Bus 721, B-3000 Leuven, Belgium. E-mail: annelies.devesse@kuleuven.be Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

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