Neural Envelope Processing at Low Frequencies Predicts Speech Understanding of Children With Hearing Loss in Noise and Reverberation.

OBJECTIVE: Children with hearing loss experience greater difficulty understanding speech in the presence of noise and reverberation relative to their normal hearing peers despite provision of appropriate amplification. The fidelity of fundamental frequency of voice (f0) encoding-a salient temporal cue for understanding speech in noise-could play a significant role in explaining the variance in abilities among children. However, the nature of deficits in f0 encoding and its relationship with speech understanding are poorly understood. To this end, we evaluated the influence of frequency-specific f0 encoding on speech perception abilities of children with and without hearing loss in the presence of noise and/or reverberation. METHODS: In 14 school-aged children with sensorineural hearing loss fitted with hearing aids and 29 normal hearing peers, envelope following responses (EFRs) were elicited by the vowel /i/, modified to estimate f0 encoding in low (<1.1 kHz) and higher frequencies simultaneously. EFRs to /i/ were elicited in quiet, in the presence of speech-shaped noise at +5 dB signal to noise ratio, with simulated reverberation time of 0.62 sec, as well as both noise and reverberation. EFRs were recorded using single-channel electroencephalogram between the vertex and the nape while children watched a silent movie with captions. Speech discrimination accuracy was measured using the University of Western Ontario Distinctive Features Differences test in each of the four acoustic conditions. Stimuli for EFR recordings and speech discrimination were presented monaurally. RESULTS: Both groups of children demonstrated a frequency-dependent dichotomy in the disruption of f0 encoding, as reflected in EFR amplitude and phase coherence. Greater disruption (i.e., lower EFR amplitudes and phase coherence) was evident in EFRs elicited by low frequencies due to noise and greater disruption was evident in EFRs elicited by higher frequencies due to reverberation. Relative to normal hearing peers, children with hearing loss demonstrated: (a) greater disruption of f0 encoding at low frequencies, particularly in the presence of reverberation, and (b) a positive relationship between f0 encoding at low frequencies and speech discrimination in the hardest listening condition (i.e., when both noise and reverberation were present). CONCLUSIONS: Together, these results provide new evidence for the persistence of suprathreshold temporal processing deficits related to f0 encoding in children despite the provision of appropriate amplification to compensate for hearing loss. These objectively measurable deficits may underlie the greater difficulty experienced by children with hearing loss.

Development and Evaluation of a Language-Independent Test of Auditory Discrimination for Referrals for Cochlear Implant Candidacy Assessment.

OBJECTIVES: The purpose of this study was to (1) develop a Language-independent Test of Auditory Discrimination (LIT-AD) between speech sounds so that people with hearing loss who derive limited speech perception benefits from hearing aids (HAs) may be identified for consideration of cochlear implantation and (2) examine the relationship between the scores for the new discrimination test and those of a standard sentence test for adults wearing either HAs or cochlear implants (CIs). DESIGN: The test measures the ability of the listener to correctly discriminate pairs of nonsense syllables, presented as sequential triplets in an odd-one-out format, implemented as a game-based software tool for self-administration using a tablet computer. Stage 1 included first a review of phonemic inventories in the 40 most common languages in the world to select the consonants and vowels. Second, discrimination testing of 50 users of CIs at several signal to noise ratios (SNRs) was carried out to generate psychometric functions. These were used to calculate the corrections in SNR for each consonant-pair and vowel combination required to equalize difficulty across items. Third, all items were individually equalized in difficulty and the overall difficulty set. Stage 2 involved the validation of the LIT-AD in English-speaking listeners by comparing discrimination scores with performance in a standard sentence test. Forty-one users of HAs and 40 users of CIs were assessed. Correlation analyses were conducted to examine test-retest reliability and the relationship between performance in the two tests. Multiple regression analyses were used to examine the relationship between demographic characteristics and performance in the LIT-AD. The scores of the CI users were used to estimate the probability of superior performance with CIs for a non-CI user having a given LIT-AD score and duration of hearing loss. RESULTS: The LIT-AD comprises 81 pairs of vowel-consonant-vowel syllables that were equalized in difficulty to discriminate. The test can be self-administered on a tablet computer, and it takes about 10 min to complete. The software automatically scores the responses and gives an overall score and a list of confusable items as output. There was good test-retest reliability. On average, higher LIT-AD discrimination scores were associated with better sentence perception for users of HAs (r = -0.54, p <0.001) and users of CIs (r = -0.73, p <0.001). The probability of superior performance with CIs for a certain LIT-AD score was estimated, after allowing for the effect of duration of hearing loss. CONCLUSIONS: The LIT-AD could increase access to CIs by screening for those who obtain limited benefits from HAs to facilitate timely referrals for CI candidacy evaluation. The test results can be used to provide patients and professionals with practical information about the probability of potential benefits for speech perception from cochlear implantation. The test will need to be evaluated for speakers of languages other than English to facilitate adoption in different countries.

The Relations Between Auditory Processing Scores and Cognitive, Listening and Reading Abilities.

OBJECTIVES: To investigate associations between auditory processing abilities, cognitive abilities, listening ability, and reading ability in children. DESIGN: This was a cross-sectional study involving 155 children (105 referred for auditory processing assessment and 50 with no reported listening concerns) aged between 7 and 13 years. Each child was assessed on auditory processing tests, cognitive tests, and a reading test. Additional data on reading ability were provided by the reading score from a national test. Questionnaires about the child's listening ability were completed by a parent, a teacher, and the child. RESULTS: Structural equation models relating auditory processing abilities, cognitive abilities, listening ability, and reading ability were developed. There was evidence that listening and reading abilities were associated with cognitive abilities when adjusting for auditory processing abilities, but little evidence that listening and reading abilities were associated with auditory processing abilities when adjusting for cognitive abilities. CONCLUSIONS: It should not be assumed that auditory processing tests and cognitive tests measure separate abilities. When investigating the association between auditory processing abilities and real-world abilities, it is important to adjust for cognitive abilities. Children with listening difficulties should undergo cognitive assessments in addition to auditory processing assessments.

Determining unilateral or bilateral hearing aid preference in adults: a prospective study.

OBJECTIVE: Despite high rates of bilateral hearing aid fitting globally, a number of adults continue to reject one hearing aid. The current study aimed to identify a clinically suitable tool for determining, pre-fitting, which clients might prefer one hearing aid.Study Sample: Ninety-five new adult hearing aid candidates, aged 49-87 years, were assessed prior to a first hearing aid fitting. Sixty-eight participants adhered to the prescribed protocol for both bilateral and unilateral hearing aid use. DESIGN: Performance was assessed on a modified version of the Listening in Spatialised Noise - Sentences test (LiSN-S), the Dichotic Digits difference Test, the Experiential Hearing Aid simulator, and the Grooved Pegboard Test. All participants were fitted bilaterally, but were instructed to alternate between unilateral and bilateral hearing aid use over fourteen weeks post-fitting. Participants' wearing preferences were assessed via a short questionnaire. RESULTS: 78% of participants expressed an overall preference for bilateral hearing aid use. Only the LiSN-S bilateral advantage test outcomes significantly correlated with overall wearing preference. CONCLUSIONS: Although the LiSN-S bilateral advantage score related to overall wearing preference, the accuracy of the predictor was too low to warrant implementation of this test prior to hearing aid fitting. The current practice of recommending bilateral hearing aid use continues to be the best option for clinicians.

Automated cortical auditory response detection strategy.

Objective: This study describes a new automated strategy to determine the detection status of an electrophysiological response.Design: Response, noise and signal-to-noise ratio of the cortical auditory evoked potential (CAEP) were characterised. Detection rules were defined: when to start testing, when to conduct subsequent statistical tests using residual noise as an objective criterion, and when to stop testing.Study sample: Simulations were run to determine optimal parameters on a large combined CAEP data set collected in 45 normal-hearing adults and 17 adults with hearing loss.Results: The proposed strategy to detect CAEPs is fully automated. The first statistical test is conducted when the residual noise level is equal to or smaller than 5.1 µV. The succeeding Hotelling's T2 statistical tests are conducted using pre-defined residual noise levels criteria ranging from 5.1 to 1.2 µV. A rule was introduced allowing to stop testing before the maximum number of recorded epochs is reached, depending on a minimum p-value criterion.Conclusion: The proposed framework can be applied to systems which involves detection of electrophysiological responses in biological systems containing background noise. The proposed detection algorithm which optimise sensitivity, specificity, and recording time has the potential to be used in clinical setting.

Poorer Speech Reception Threshold in Noise Is Associated With Lower Brain Volume in Auditory and Cognitive Processing Regions.

Purpose Hearing loss is associated with changes in brain volume in regions supporting auditory and cognitive processing. The purpose of this study was to determine whether there is a systematic association between hearing ability and brain volume in cross-sectional data from a large nonclinical cohort of middle-aged adults available from the UK Biobank Resource ( http://www.ukbiobank.ac.uk ). Method We performed a set of regression analyses to determine the association between speech reception threshold in noise (SRTn) and global brain volume as well as predefined regions of interest (ROIs) based on T1-weighted structural images, controlling for hearing-related comorbidities and cognition as well as demographic factors. In a 2nd set of analyses, we additionally controlled for hearing aid (HA) use. We predicted statistically significant associations globally and in ROIs including auditory and cognitive processing regions, possibly modulated by HA use. Results Whole-brain gray matter volume was significantly lower for individuals with poorer SRTn. Furthermore, the volume of 9 predicted ROIs including both auditory and cognitive processing regions was lower for individuals with poorer SRTn. The greatest percentage difference (-0.57%) in ROI volume relating to a 1 SD worsening of SRTn was found in the left superior temporal gyrus. HA use did not substantially modulate the pattern of association between brain volume and SRTn. Conclusions In a large middle-aged nonclinical population, poorer hearing ability is associated with lower brain volume globally as well as in cortical and subcortical regions involved in auditory and cognitive processing, but there was no conclusive evidence that this effect is moderated by HA use. This pattern of results supports the notion that poor hearing leads to reduced volume in brain regions recruited during speech understanding under challenging conditions. These findings should be tested in future longitudinal, experimental studies. Supplemental Material https://doi.org/10.23641/asha.7949357.

Spoken language and everyday functioning in 5-year-old children using hearing aids or cochlear implants.

OBJECTIVE: This study investigated the factors influencing 5-year language, speech and everyday functioning of children with congenital hearing loss. DESIGN: Standardised tests including PLS-4, PPVT-4 and DEAP were directly administered to children. Parent reports on language (CDI) and everyday functioning (PEACH) were collected. Regression analyses were conducted to examine the influence of a range of demographic variables on outcomes. STUDY SAMPLE: Participants were 339 children enrolled in the Longitudinal Outcomes of Children with Hearing Impairment (LOCHI) study. RESULTS: Children's average receptive and expressive language scores were approximately 1 SD below the mean of typically developing children, and scores on speech production and everyday functioning were more than 1 SD below. Regression models accounted for 70-23% of variance in scores across different tests. Earlier CI switch-on and higher non-verbal ability were associated with better outcomes in most domains. Earlier HA fitting and use of oral communication were associated with better outcomes on directly administered language assessments. Severity of hearing loss and maternal education influenced outcomes of children with HAs. The presence of additional disabilities affected outcomes of children with CIs. CONCLUSIONS: The findings provide strong evidence for the benefits of early HA fitting and early CI for improving children's outcomes.

Age at Intervention for Permanent Hearing Loss and 5-Year Language Outcomes.

OBJECTIVES: Universal newborn hearing screening has been implemented to detect permanent childhood hearing loss (PCHL) early, with the ultimate goal of improving outcomes through early treatment. However, there is disagreement between studies on the size of this benefit and in some cases whether it is significantly different from 0. There have been no studies of sufficient size in which researchers have determined reliably whether the effect varies with degree of PCHL. We aimed to explore how intervention timing influences 5-year language in children with PCHL. METHODS: Via a prospective study of 350 children, we used standard multiple regression analyses to investigate the effect of age at intervention or hearing screening on language outcomes after allowing for the effects of nonverbal IQ, degree of PCHL, sex, birth weight, maternal education, additional disabilities, and communication mode. RESULTS: The benefit of early intervention for language development increased as hearing loss increased. Children whose amplification started at age 24 months had poorer language than those whose amplification started at 3 months. The difference was larger for 70-dB HL (-11.8 score points; 95% confidence interval [95% CI]: -18.7 to -4.8) than for 50-dB HL (-6.8; 95% CI: -10.8 to -2.8). Children who received cochlear implants at 24 months had poorer language than those implanted at 6 months (-21.4; 95% CI: -33.8 to -9.0). There was no significant effect of screening on outcomes. CONCLUSIONS: Early intervention improves language outcomes, thereby lending support to streamlining clinical pathways to ensure early amplification and cochlear implantation after diagnosis.

The Influence of Social Interaction and Physical Health on the Association Between Hearing and Depression With Age and Gender.

Recent epidemiological data suggest the relation between hearing difficulty and depression is more evident in younger and middle-aged populations than in older adults. There are also suggestions that the relation may be more evident in specific subgroups; that is, other factors may influence a relationship between hearing and depression in different subgroups. Using cross-sectional data from the UK Biobank on 134,357 community-dwelling people and structural equation modelling, this study examined the potential mediating influence of social isolation and unemployment and the confounding influence of physical illness and cardiovascular conditions on the relation between a latent hearing variable and both a latent depressive episodes variable and a latent depressive symptoms variable. The models were stratified by age (40s, 50s, and 60s) and gender and further controlled for physical illness and professional support in associations involving social isolation and unemployment. The latent hearing variable was primarily defined by reported hearing difficulty in noise. For all subgroups, poor hearing was significantly related to both more depressive episodes and more depressive symptoms. In all models, the direct and generally small association exceeded the indirect associations via physical health and social interaction. Significant (depressive episodes) and near significant (depressive symptoms) higher direct associations were estimated for males in their 40s and 50s than for males in their 60s. There was at each age-group no significant difference in estimated associations across gender. Irrespective of the temporal order of variables, findings suggest that audiological services should facilitate psychosocial counselling.

Evaluation of the Self-Fitting Process with a Commercially Available Hearing Aid.

BACKGROUND: Hearing aids and personal sound amplification products that are designed to be self-fitted by the user at home are becoming increasingly available in the online marketplace. While these devices are often marketed as a low-cost alternative to traditional hearing health-care, little is known about people's ability to successfully use and manage them. Previous research into the individual components of a simulated self-fitting procedure has been undertaken, but no study has evaluated performance of the procedure as a whole using a commercial product. PURPOSE: To evaluate the ability of a group of adults with a hearing loss to set up a pair of commercially available self-fitting hearing aids for their own use and to investigate factors associated with a successful outcome. RESEARCH DESIGN: An interventional study that used regression analysis to identify potential contributors to the outcome. STUDY SAMPLE: Forty adults with mild to moderately severe hearing loss participated in the study: 20 current hearing aid users (the "experienced" group) and 20 with no previous amplification experience (the "new" group). Twenty-four participants attended with partners, who were present to offer assistance with the study task as needed. DATA COLLECTION AND ANALYSIS: Participants followed a set of written, illustrated instructions to perform a multistep self-fitting procedure with a commercially available self-fitting hearing aid, with optional assistance from a lay partner. Standardized measures of cognitive function, health literacy, locus of control, hearing aid self-efficacy, and manual dexterity were collected. Statistical analysis was performed to examine the proportion of participants in each group who successfully performed the self-fitting procedure, factors that predicted successful completion of the task, and the contributions of partners to the outcome. RESULTS: Fifty-five percent of participants were able to successfully perform the self-fitting procedure. Although the same success rate was observed for both experienced and new participants, the majority of the errors relating to the hearing test and the fine-tuning tasks were made by the experienced participants, while all of the errors associated with physically customizing the hearing aids and most of the insertion errors were made by the new participants. Although the majority of partners assisted in the self-fitting task, their contributions did not significantly influence the outcome. Further, no characteristic or combination of characteristics reliably predicted which participants would be successful at the self-fitting task. CONCLUSIONS: Although the majority of participants were able to complete the self-fitting task without error, the provision of knowledgeable support by trained personnel, rather than a fellow layperson, would most certainly increase the proportion of users who are able to achieve success. Refinements to the instructions and the physical design of the hearing aid may also serve to improve the success rate. Further evaluation of the range of self-fitting hearing aids that are now on the market should be undertaken.

The Effect of Functional Hearing and Hearing Aid Usage on Verbal Reasoning in a Large Community-Dwelling Population.

OBJECTIVES: Verbal reasoning performance is an indicator of the ability to think constructively in everyday life and relies on both crystallized and fluid intelligence. This study aimed to determine the effect of functional hearing on verbal reasoning when controlling for age, gender, and education. In addition, the study investigated whether hearing aid usage mitigated the effect and examined different routes from hearing to verbal reasoning. DESIGN: Cross-sectional data on 40- to 70-year-old community-dwelling participants from the UK Biobank resource were accessed. Data consisted of behavioral and subjective measures of functional hearing, assessments of numerical and linguistic verbal reasoning, measures of executive function, and demographic and lifestyle information. Data on 119,093 participants who had completed hearing and verbal reasoning tests were submitted to multiple regression analyses, and data on 61,688 of these participants, who had completed additional cognitive tests and provided relevant lifestyle information, were submitted to structural equation modeling. RESULTS: Poorer performance on the behavioral measure of functional hearing was significantly associated with poorer verbal reasoning in both the numerical and linguistic domains (p < 0.001). There was no association between the subjective measure of functional hearing and verbal reasoning. Functional hearing significantly interacted with education (p < 0.002), showing a trend for functional hearing to have a greater impact on verbal reasoning among those with a higher level of formal education. Among those with poor hearing, hearing aid usage had a significant positive, but not necessarily causal, effect on both numerical and linguistic verbal reasoning (p < 0.005). The estimated effect of hearing aid usage was less than the effect of poor functional hearing. Structural equation modeling analyses confirmed that controlling for education reduced the effect of functional hearing on verbal reasoning and showed that controlling for executive function eliminated the effect. However, when computer usage was controlled for, the eliminating effect of executive function was weakened. CONCLUSIONS: Poor functional hearing was associated with poor verbal reasoning in a 40- to 70-year-old community-dwelling population after controlling for age, gender, and education. The effect of functional hearing on verbal reasoning was significantly reduced among hearing aid users and completely overcome by good executive function skills, which may be enhanced by playing computer games.

Pure tone hearing thresholds and leisure noise: Is there a relationship?

This paper reports on the examination of the relationship between self-reported historical noise exposure during leisure activities and audiological indicators: Measured hearing threshold levels (HTLs) and otoacoustic emissions (OAEs). The research was conducted by a cross-sectional survey of 1,432 individuals whose ages ranged from 11 years to 35 years. Methodology included a comprehensive audiometric assessment including otoscopy, pure tone audiometry (PTA) (air- and bone-conduction), OAEs, and tympanometry. A comprehensive questionnaire gathered information on demographics, hearing health status, and participation in work, non-work, and leisure activities. Using the history of work, non-work, and leisure noise exposure, a cumulative lifetime noise exposure was estimated. No correlation was found between cumulative lifetime noise exposure and audiometric PTA or OAE parameters.

TE and DP otoacoustic emission data from an Australian cross-sectional hearing study.

OBJECTIVE: This paper presents a summary of otoacoustic emission (OAE) data collected as part of an Australian hearing health survey ( Carter, 2011 ; Williams et al, 2014 ) designed to: (1) examine the relationship between audiological indicators and participant characteristics, and (2) extract audiological data suitable for reference use. DESIGN: Cross-sectional cohort study. Distortion product (DP) OAE and transient evoked (TE) OAE measures. STUDY SAMPLE: Age range 11-35 years; N = 1386 participants (2672 test ears). RESULTS: Descriptive statistics for amplitude and signal-to-noise ratio (SNR) were calculated for 327 participants (589 test ears; age 13 to 32 years). DPOAE amplitudes down to the 25th percentile were > 0 dB SPL for test frequencies up to 6 kHz. TEOAE SNRs down to the 25th percentile were > 6 dB SPL up to 4 kHz. SUMMARY: This dataset can be used as a clinical reference for similar populations, providing that the same test parameters are used. CONCLUSIONS: The clinical significance of OAE testing would be greater if agreed criteria were available. These data could be pooled with other datasets to build a substantial OAE database, similar to the existing international standards for pure-tone hearing threshold levels (HTLs) ( ISO, 2000 ).

Factors Affecting Psychosocial and Motor Development in 3-Year-Old Children Who Are Deaf or Hard of Hearing.

Previous research has shown an association between children's development of psychosocial and motor skills. This study evaluated the development of these skills in 301 three-year-old deaf and hard of hearing children (M: 37.8 months) and considered a range of possible predictors including gender, birth weight, age at first fitting with hearing devices, hearing device used, presence of additional disabilities, severity of hearing loss, maternal education, socio-economic status (SES), language ability, and communication mode. Caregivers reported on children's development using the Child Development Inventory (CDI). On average, both psychosocial and motor development quotients were within the typical range for hearing children, with large individual differences. There was a positive correlation between language ability and both social and motor development, and also between social and motor development. Age at first fitting of hearing aids (as an indicator of age at identification of hearing loss), SES, degree of hearing loss, and maternal education were not significant predictors of social skill or motor development, whereas presence of additional disabilities and birth weight were. Girls performed better than boys on all but the Gross Motor subscale of the CDI. Children with hearing aids tended to perform better than those with cochlear implants on the Gross Motor subscale.

On the relationship between functional hearing and depression.

OBJECTIVE: To establish the effect of self-rated and measured functional hearing on depression, taking age and gender into account. Additionally, the study investigates if hearing-aid usage mitigates the effect, and if other physical health problems and social engagement confound it. DESIGN: Cross-sectional data from the UK Biobank resource, including subjective and behavioural measures of functional hearing and multifactorial measures of depressive episodes and symptoms, were accessed and analysed using multi-regression analyses. STUDY SAMPLE: Over 100 000 community-dwelling, 39-70 year-old volunteers. RESULTS: Irrespective of measurement method, poor functional hearing was significantly (p < 0.001) associated with higher levels of depressive episodes (≤ 0.16 factor scores) and depressive symptoms (≤ 0.30 factor scores) when controlling for age and gender. Associations were stronger for subjective reports, for depressive symptoms, and the younger participants. Females generally reported higher levels of depression. Hearing-aid usage did not show a mitigating effect on the associations. Other physical health problems particularly partially confounded the effects. CONCLUSION: Data support an association between functional hearing and depression that is stronger in the younger participants (40-49 years old) and for milder depression. The association was not alleviated by hearing-aid usage, but was partially confounded by other physical health problems.

Estimating Hearing Thresholds in Hearing-Impaired Adults through Objective Detection of Cortical Auditory Evoked Potentials.

BACKGROUND: Hearing threshold estimation based on cortical auditory evoked potentials (CAEPs) has been applied for some decades. However, available research is scarce evaluating the accuracy of this technique with an automated paradigm for the objective detection of CAEPs. PURPOSE: To determine the difference between behavioral and CAEP thresholds detected using an objective paradigm based on the Hotelling's T² statistic. To propose a decision tree to choose the next stimulus level in a sample of hearing-impaired adults. This knowledge potentially could increase the efficiency of clinical hearing threshold testing. RESEARCH DESIGN: Correlational cohort study. Thresholds obtained behaviorally were compared with thresholds obtained through cortical testing. STUDY SAMPLE: Thirty-four adults with hearing loss participated in this study. DATA COLLECTION AND ANALYSIS: For each audiometric frequency and each ear, behavioral thresholds were collected with both pure-tone and 40-msec tone-burst stimuli. Then, corresponding cortical hearing thresholds were determined. An objective cortical-response detection algorithm based on the Hotelling's T² statistic was applied to determine response presence. A decision tree was used to select the next stimulus level. In total, 241 behavioral-cortical threshold pairs were available for analysis. The differences between CAEP and behavioral thresholds (and their standard deviations [SDs]) were determined for each audiometric frequency. Cortical amplitudes and electroencephalogram noise levels were extracted. The practical applicability of the decision tree was evaluated and compared to a Hughson-Westlake paradigm. RESULTS: It was shown that, when collapsed over all audiometric frequencies, behavioral pure-tone thresholds were on average 10 dB lower than 40-msec cortical tone-burst thresholds, with an SD of 10 dB. Four percent of CAEP thresholds, all obtained from just three individual participants, were more than 30 dB higher than their behavioral counterparts. The use of a decision tree instead of a Hughson-Westlake procedure to obtain a CAEP threshold did not seem to reduce test time, but there was significantly less variation in the number of CAEP trials needed to determine a threshold. CONCLUSIONS: Behavioral hearing thresholds in hearing-impaired adults can be determined with an acceptable degree of accuracy (mean threshold correction and SD of both 10 dB) using an objective statistical cortical-response detection algorithm in combination with a decision tree to determine the test levels.

Factors affecting reliability and validity of self-directed automatic in situ audiometry: implications for self-fitting hearing AIDS.

BACKGROUND: A reliable and valid method for the automatic in situ measurement of hearing thresholds is a prerequisite for the feasibility of a self-fitting hearing aid, whether such a device becomes an automated component of an audiological management program or is fitted by the user independently of a clinician. Issues that must be addressed before implementation of the procedure into a self-fitting hearing aid include the role of real-ear-to-dial difference correction factors in ensuring accurate results and the ability of potential users to successfully self-direct the procedure. PURPOSE: The purpose of this study was to evaluate the reliability and validity of an automatic audiometry algorithm that is fully implemented in a wearable hearing aid, to determine to what extent reliability and validity are affected when the procedure is self-directed by the user, and to investigate contributors to a successful outcome. RESEARCH DESIGN: Design was a two-phase correlational study. STUDY SAMPLE: A total of 60 adults with mild to moderately severe hearing loss participated in both studies: 20 in Study 1 and 40 in Study 2. Twenty-seven participants in Study 2 attended with a partner. Participants in both phases were selected for inclusion if their thresholds were within the output limitations of the test device. DATA COLLECTION AND ANALYSIS: In both phases, participants performed automatic audiometry through a receiver-in-canal, behind-the-ear hearing aid coupled to an open dome. In Study 1, the experimenter directed the task. In Study 2, participants followed a set of written, illustrated instructions to perform automatic audiometry independently of the experimenter, with optional assistance from a lay partner. Standardized measures of hearing aid self-efficacy, locus of control, cognitive function, health literacy, and manual dexterity were administered. Statistical analysis examined the repeatability of automatic audiometry; the match between automatically and manually measured thresholds; and contributors to successful, independent completion of the automatic audiometry procedure. RESULTS: When the procedure was directed by an audiologist, automatic audiometry yielded reliable and valid thresholds. Reliability and validity were negatively affected when the procedure was self-directed by the user, but the results were still clinically acceptable: test-retest correspondence was 10 dB or lower in 97% of cases, and 91% of automatic thresholds were within 10 dB of their manual counterparts. However, only 58% of participants were able to achieve a complete audiogram in both ears. Cognitive function significantly influenced accurate and independent performance of the automatic audiometry procedure; accuracy was further affected by locus of control and level of education. Several characteristics of the automatic audiometry algorithm played an additional role in the outcome. CONCLUSIONS: Average transducer- and coupling-specific correction factors are sufficient for a self-directed in situ audiometry procedure to yield clinically reliable and valid hearing thresholds. Before implementation in a self-fitting hearing aid, however, the algorithm and test instructions should be refined in an effort to increase the proportion of users who are able to achieve complete audiometric results. Further evaluation of the procedure, particularly among populations likely to form the primary audience of a self-fitting hearing aid, should be undertaken.

Language and speech perception of young children with bimodal fitting or bilateral cochlear implants.

OBJECTIVES: This paper compares language development and speech perception of children with bimodal fitting (a cochlear implant in one ear and a hearing aid in the opposite ear) or bilateral cochlear implantation. METHODS: Participants were children enrolled in the Longitudinal Outcomes of Children with Hearing Impairment study. Language development was assessed at 3 years of age using standardized tests. Speech perception was evaluated at 5 years of age. Speech was presented from a frontal loudspeaker, and babble noise was presented either from the front or from both sides. RESULTS: On average, there was no significant difference in language outcomes between 44 children with bimodal fitting and 49 children with bilateral cochlear implants; after controlling for a range of demographic variables. Earlier age at cochlear implant activation was associated with better outcomes. Speech perception in noise was not significantly different between children with bimodal fitting and those with bilateral cochlear implants. Compared to normal-hearing children, children with cochlear implants required a better signal-to-noise ratio to perform at the same level, but demonstrated spatial release from masking of a similar magnitude. CONCLUSIONS: This population-based study found that language scores for children with bilateral implants were higher than those with bimodal fitting or those with unilateral implants, but neither reached significance level.

Predictors of Early Reading Skill in 5-Year-Old Children With Hearing Loss Who Use Spoken Language.

This research investigated the concurrent association between early reading skills and phonological awareness (PA), print knowledge, language, cognitive, and demographic variables in 101 5-year-old children with prelingual hearing losses ranging from mild to profound who communicated primarily using spoken language. All participants were fitted with hearing aids (n = 71) or cochlear implants (n = 30). They completed standardized assessments of PA, receptive vocabulary, letter knowledge, word and non-word reading, passage comprehension, math reasoning, and nonverbal cognitive ability. Multiple regressions revealed that PA (assessed using judgments of similarity based on words' initial or final sounds) made a significant, independent contribution to children's early reading ability (for both letters and words/non-words) after controlling for variation in receptive vocabulary, nonverbal cognitive ability, and a range of demographic variables (including gender, degree of hearing loss, communication mode, type of sensory device, age at fitting of sensory devices, and level of maternal education). Importantly, the relationship between PA and reading was specific to reading and did not generalize to another academic ability, math reasoning. Additional multiple regressions showed that letter knowledge (names or sounds) was superior in children whose mothers had undertaken post-secondary education, and that better receptive vocabulary was associated with less severe hearing loss, use of a cochlear implant, and earlier age at implant switch-on. Earlier fitting of hearing aids or cochlear implants was not, however, significantly associated with better PA or reading outcomes in this cohort of children, most of whom were fitted with sensory devices before 3 years of age.

Identification of conductive hearing loss using air conduction tests alone: reliability and validity of an automatic test battery.

OBJECTIVES: The primary objective of this study was to determine whether a combination of automatically administered pure-tone audiometry and a tone-in-noise detection task, both delivered via an air conduction (AC) pathway, could reliably and validly predict the presence of a conductive component to the hearing loss. The authors hypothesized that performance on the battery of tests would vary according to hearing loss type. A secondary objective was to evaluate the reliability and validity of a novel automatic audiometry algorithm to assess its suitability for inclusion in the test battery. DESIGN: Participants underwent a series of hearing assessments that were conducted in a randomized order: manual pure-tone air conduction audiometry and bone conduction audiometry; automatic pure-tone air conduction audiometry; and an automatic tone-in-noise detection task. The automatic tests were each administered twice. The ability of the automatic test battery to: (a) predict the presence of an air-bone gap (ABG); and (b) accurately measure AC hearing thresholds was assessed against the results of manual audiometry. Test-retest conditions were compared to determine the reliability of each component of the automatic test battery. Data were collected on 120 ears from normal-hearing and conductive, sensorineural, and mixed hearing-loss subgroups. RESULTS: Performance differences between different types of hearing loss were observed. Ears with a conductive component (conductive and mixed ears) tended to have normal signal to noise ratios (SNR) despite impaired thresholds in quiet, while ears without a conductive component (normal and sensorineural ears) demonstrated, on average, an increasing relationship between their thresholds in quiet and their achieved SNR. Using the relationship between these two measures among ears with no conductive component as a benchmark, the likelihood that an ear has a conductive component can be estimated based on the deviation from this benchmark. The sensitivity and specificity of the test battery vary depending on the size of this deviation, but increase with increasing ABG size, with decreasing test frequency, and when results from multiple test frequencies are taken into account. The individual automatic tests comprising the battery were found to be reliable and valid, with strong, significant correlations between the test and retest results (r = 0.81 to 0.99; p < 0.0001) and between automatic and manual audiometry procedures (r = 0.98 to 0.99; p < 0.0001). CONCLUSIONS: The presence of an ABG can be predicted with a reasonably high degree of accuracy using AC tests alone. Applications of such a test battery include any clinical context in which bone conduction audiometry or specialized diagnostic equipment is unavailable or impractical. Examples of these include self-fitting hearing aids, whose efficacy relies on the ability of the device to automatically administer an in situ hearing test; self-administered adult hearing screenings in both clinical and home environments; large-scale industrial hearing conservation programs; and test environments in which ambient noise levels exceed the maximum permissible levels for unoccluded ears.