Parent-Reported Ease of Listening in Preschool-Aged Children With Bilateral and Unilateral Hearing Loss.

OBJECTIVES: Evidence from school-aged children suggests that the ease with which children listen varies with the presence of hearing loss and the acoustic environment despite the use of devices like hearing aids. However, little is known about the ease of listening in preschool-aged children with hearing loss-an age at which rapid learning occurs and increased listening difficulty or effort may diminish the required capacity to learn new skills. To this end, the objectives of the present study were to (i) assess parent-reported aided ease of listening as a function of hearing loss configuration (hearing loss in one versus both ears) and device configuration among children with hearing loss in one ear (unilateral hearing loss), and (ii) investigate factors that influence children's ease of listening. DESIGN: Parents of 83 children with normal hearing, 54 aided children with bilateral hearing loss (hearing loss in both ears), and 139 children with unilateral hearing loss participated in the study. Of the 139 children with unilateral loss, 72 were unaided, 54 were aided with a device on the ear with hearing loss (direct aiding) and 13 were aided with a device that routed signals to the contralateral normal hearing ear (indirect aiding). Mean age of children was 40.2 months (1 SD = 2.5; range: 36 to 51). Parents completed the two subscales of the Parents' Evaluation of Aural/Oral Performance of Children+ (PEACH+) questionnaire, namely functional listening and ease of listening. Individual percent scores were computed for quiet and noisy situations. Linear mixed-effects models were used to assess the effect of hearing loss configuration and device configuration in children with unilateral hearing loss. Multiple regression was used to assess factors that influenced ease of listening. Factors included hearing thresholds, age at first device fit, consistency in device use, condition (quiet/noise), presence of developmental disabilities, and functional listening abilities. RESULTS: Children with direct aiding for their hearing loss, either unilateral or bilateral, had similarly lower functional listening skills and ease of listening than their normal hearing peers. Unaided children with unilateral hearing loss had lower functional listening skills and ease of listening than their normal hearing peers in noise but not in quiet. All aided children with unilateral hearing loss, irrespective of direct or indirect aiding had lower functional listening skills and ease of listening relative to normal hearing children in both quiet and noise. Furthermore, relative to unaided children with unilateral hearing loss, those with indirect aiding had lower functional listening and ease of listening. Regression analyses revealed functional listening as a significant predictor of ease of listening in all children with hearing loss. In addition, worse degrees of hearing loss and presence of noise reduced ease of listening in unaided children with unilateral hearing loss. CONCLUSIONS: Bilateral hearing loss is associated with poorer-than-typical ease of listening in preschoolers even when aided. The impact of unilateral hearing loss on ease of listening is similar to that observed in children with bilateral hearing loss, despite good hearing in one ear and aiding. Given increased difficulties experienced by children with unilateral loss, with or without a device, additional strategies to facilitate communication abilities in noise should be a priority.

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.

Programming characteristics of cochlear implants in children: effects of aetiology and age at implantation.

OBJECTIVE: We investigated effects of aetiology and age at implantation on changes in threshold (T) levels, comfortable (C) levels and dynamic range (DR) for cochlear implants (CIs) in children over the first five years of life. DESIGN: Information was collected at 6 months post-activation of CIs, and at 3 and 5 years of age. STUDY SAMPLE: One hundred and sixty-one children participating in the Longitudinal Outcomes of Children with Hearing Impairment (LOCHI) study. RESULTS: Children with neural and structural cochlear lesions had higher T-levels and C-levels as compared to those without these conditions. Parameter settings varied from manufacturer's defaults more often in the former than in the latter group. Investigation of the effect of age at implantation for children without neural and structural cochlear lesions showed that those implanted at ≤12 months of age had higher T-levels and narrower DR at 6 months post-activation, as compared to the later-implanted group. For both early- and later-implanted groups, the C-levels at 6 months post-activation were lower than those at age 3 and 5 years. There were no significant differences in T-levels, C-levels, or DR between age 3 and 5 years. CONCLUSIONS: Aetiology and age at implantation had significant effects on T-levels and C-levels.

Factors influencing speech perception in noise for 5-year-old children using hearing aids or cochlear implants.

OBJECTIVE: We investigated the factors influencing speech perception in babble for 5-year-old children with hearing loss who were using hearing aids (HAs) or cochlear implants (CIs). DESIGN: Speech reception thresholds (SRTs) for 50% correct identification were measured in two conditions - speech collocated with babble, and speech with spatially separated babble. The difference in SRTs between the two conditions give a measure of binaural unmasking, commonly known as spatial release from masking (SRM). Multiple linear regression analyses were conducted to examine the influence of a range of demographic factors on outcomes. STUDY SAMPLE: Participants were 252 children enrolled in the Longitudinal Outcomes of Children with Hearing Impairment (LOCHI) study. RESULTS: Children using HAs or CIs required a better signal-to-noise ratio to achieve the same level of performance as their normal-hearing peers but demonstrated SRM of a similar magnitude. For children using HAs, speech perception was significantly influenced by cognitive and language abilities. For children using CIs, age at CI activation and language ability were significant predictors of speech perception outcomes. CONCLUSIONS: Speech perception in children with hearing loss can be enhanced by improving their language abilities. Early age at cochlear implantation was also associated with better outcomes.

Hearing aid fitting and developmental outcomes of children fit according to either the NAL or DSL prescription: fit-to-target, audibility, speech and language abilities.

OBJECTIVE: This study examined the influence of prescription on hearing aid (HA) fitting characteristics and 5-year developmental outcomes of children. DESIGN: A randomised controlled trial implemented as part of a population-based study on Longitudinal Outcomes of Children with Hearing Impairment (LOCHI). STUDY SAMPLE: Two-hundred and thirty-two children that were fit according to either the National Acoustic Laboratories (NAL) or Desired Sensation Level (DSL) prescription. RESULTS: Deviation from targets and root-mean-square error in HA fitting revealed no significant difference between fitting prescriptions. Aided audibility quantified by using the Speech Intelligibility Index (SII) model showed that DSL provided higher audibility than NAL at low and medium input levels but not at high input level. After allowing for hearing loss desensitisation, differences in audibility between prescription groups were significant only at low input level. The randomised trial of prescription that was implemented for 163 children revealed no significant between-group differences in speech production, perception, and language; but parent-rated functional performance was higher for the DSL than for the NAL group. CONCLUSIONS: Proximity to prescriptive targets was similar between fitting prescriptions. The randomised trial revealed differences in aided audibility at low input level between prescription groups, but no significant differences in speech and language abilities.

Speech, language, functional communication, psychosocial outcomes and QOL in school-age children with congenital unilateral hearing loss.

Introduction: Children with early-identified unilateral hearing loss (UHL) might be at risk for delays in early speech and language, functional communication, psychosocial skills, and quality of life (QOL). However, a paucity of relevant research prohibits strong conclusions. This study aimed to provide new evidence relevant to this issue. Methods: Participants were 34 children, ages 9;0 to 12;7 (years;months), who were identified with UHL via newborn hearing screening. Nineteen children had been fitted with hearing devices, whereas 15 had not. Assessments included measures of speech perception and intelligibility; language and cognition; functional communication; psychosocial abilities; and QOL. Results and discussion: As a group, the children scored significantly below the normative mean and more than one standard deviation below the typical range on speech perception in spatially separated noise, and significantly below the normative mean on written passage comprehension. Outcomes in other aspects appear typical. There was however considerable within participant variation in the children's degree of hearing loss over time, raising the possibility that this pattern of results might change as children get older. The current study also revealed that participants with higher levels of nonverbal ability demonstrated better general language skills and better ability to comprehend written passages. By contrast, neither perception of speech in collocated noise nor fitting with a hearing device accounted for unique variance in outcome measures. Future research should, however, evaluate the fitting of hearing devices using random assignment of participants to groups in order to avoid any confounding influence of degree of hearing loss or children's past/current level of progress.

Effects of automatic auditory scene classification on speech perception in noise and real-world functional communication in children using cochlear implants.

OBJECTIVES: To investigate the effects of automatic scene classification (SCAN) on speech perception in noise and real-world functional performance in children using cochlear implants (CIs). METHODS: We used a within-subjects repeated measures design in two studies. The first study assessed speech perception in noise with or without SCAN enabled in 25 school-aged children. The second study evaluated functional auditory performance in real life. Parents of 18 children provided ratings using the Parents' Evaluation of Aural/oral Performance of Children (PEACH) questionnaire; and children provided ratings using the Self Evaluation of Listening Function (SELF) questionnaire. Analyses of variance with repeated measures were used to examine the effect of SCAN. RESULTS: On average, speech perception in noise was significantly better with SCAN enabled (mean SRT: -4.1 dB; SD: 4.0), compared to SCAN disabled (mean SRT: 0.5 dB; SD: 3.5). Children's functional performance in real life was similar between the two device settings. CONCLUSION: Automatic auditory scene classification provides significant benefits for speech perception in noise (4.6 dB improvement). On average, there were no perceived detrimental or beneficial effects in real life. These findings support the use of SCAN in CIs for young children.

Outcomes of early- and late-identified children at 3 years of age: findings from a prospective population-based study.

OBJECTIVE: To address the question of whether, on a population level, early detection and amplification improve outcomes of children with hearing impairment. DESIGN: All families of children who were born between 2002 and 2007, and who presented for hearing services below 3 years of age at Australian Hearing pediatric centers in New South Wales, Victoria, and Southern Queensland were invited to participate in a prospective study on outcomes. Children's speech, language, functional, and social outcomes were assessed at 3 years of age, using a battery of age-appropriate tests. Demographic information relating to the child, family, and educational intervention was solicited through the use of custom-designed questionnaires. Audiological data were collected from the national database of Australian Hearing and records held at educational intervention agencies for children. Regression analysis was used to investigate the effects of each of 15 predictor variables, including age of amplification, on outcomes. RESULTS: Four hundred and fifty-one children enrolled in the study, 56% of whom received their first hearing aid fitting before 6 months of age. On the basis of clinical records, 44 children (10%) were diagnosed with auditory neuropathy spectrum disorder. There were 107 children (24%) reported to have additional disabilities. At 3 years of age, 317 children (70%) were hearing aid users and 134 children (30%) used cochlear implants. On the basis of parent reports, about 71% used an aural/oral mode of communication, and about 79% used English as the spoken language at home. Children's performance scores on standardized tests administered at 3 years of age were used in a factor analysis to derive a global development factor score. On average, the global score of hearing-impaired children was more than 1 SD below the mean of normal-hearing children at the same age. Regression analysis revealed that five factors, including female gender, absence of additional disabilities, less severe hearing loss, higher maternal education, and (for children with cochlear implants) earlier age of switch-on were associated with better outcomes at the 5% significance level. Whereas the effect of age of hearing aid fitting on child outcomes was weak, a younger age at cochlear implant switch-on was significantly associated with better outcomes for children with cochlear implants at 3 years of age. CONCLUSIONS: Fifty-six percent of the 451 children were fitted with hearing aids before 6 months of age. At 3 years of age, 134 children used cochlear implants and the remaining children used hearing aids. On average, outcomes were well below population norms. Significant predictors of child outcomes include: presence/absence of additional disabilities, severity of hearing loss, gender, maternal education, together with age of switch-on for children with cochlear implants.

A comparison of NAL and DSL prescriptive methods for paediatric hearing-aid fitting: predicted speech intelligibility and loudness.

OBJECTIVE: To examine the impact of prescription on predicted speech intelligibility and loudness for children. DESIGN: A between-group comparison of speech intelligibility index (SII) and loudness, based on hearing aids fitted according to NAL-NL1, DSL v4.1, or DSL m[i/o] prescriptions. A within-group comparison of gains prescribed by DSL m[i/o] and NAL-NL2 for children in terms of SII and loudness. STUDY SAMPLE: Participants were 200 children, who were randomly assigned to first hearing-aid fitting with either NAL-NL1, DSL v4.1, or DSL m[i/o]. Audiometric data and hearing-aid data at 3 years of age were used. RESULTS: On average, SII calculated on the basis of hearing-aid gains were higher for DSL than for NAL-NL1 at low input level, equivalent at medium input level, and higher for NAL-NL1 than DSL at high input level. Greater loudness was associated with DSL than with NAL-NL1, across a range of input levels. Comparing NAL-NL2 and DSL m[i/o] target gains revealed higher SII for the latter at low input level. SII was higher for NAL-NL2 than for DSL m[i/o] at medium- and high-input levels despite greater loudness for gains prescribed by DSL m[i/o] than by NAL-NL2. CONCLUSION: The choice of prescription has minimal effects on speech intelligibility predictions but marked effects on loudness predictions.

Impact of the presence of auditory neuropathy spectrum disorder (ANSD) on outcomes of children at three years of age.

OBJECTIVE: To determine the influence of the presence of auditory neuropathy spectrum disorder (ANSD) on speech, language, and psycho-social development of children at three years of age. DESIGN: A population-based, longitudinal study was performed on outcomes of children with hearing impairment (LOCHI) in Australia. The demographic characteristics of the children were described, and their developmental outcomes were evaluated at three years of age. Performance of children with ANSD was compared with that of children without ANSD in the LOCHI study. STUDY SAMPLE: There were 47 children with ANSD in the study sample. RESULTS: Sixty-four percent of children with ANSD have hearing sensitivity loss ranging from mild to severe degree, and the remaining have profound hearing loss. At three years, 27 children used hearing aids, 19 used cochlear implants, and one child did not use any hearing device. Thirty percent of children have disabilities in addition to hearing loss. On average, there were no significant differences in performance level between children with and without ANSD. Also, the variability of scores was not significantly different between the two groups. CONCLUSIONS: There was no significant difference in performance levels or variability between children with and without ANSD, both for children who use hearing aids, and children who use cochlear implants.

A randomized controlled trial of nonlinear frequency compression versus conventional processing in hearing aids: speech and language of children at three years of age.

OBJECTIVE: To determine the effect of nonlinear frequency compression (NLFC) on children's development of speech and language at three years of age. DESIGN: A randomized controlled trial was conducted as part of the population-based longitudinal study on outcomes of children with hearing impairment (LOCHI). Participants were randomly assigned to fitting with NLFC (Phonak Naida V SP or UP) or with conventional processing in hearing aids, prescribed by using either the NAL or the DSL formula. Standardized tests of speech production, receptive and expressive language were administered, and parent ratings were collected. All assessments were double-blinded. STUDY SAMPLE: Participants were 44 of the 450 children in the LOCHI cohort. RESULTS: Compared to children using conventional processing, receptive and expressive language was higher but receptive vocabulary and consonant articulation scores were lower for children who use NLFC. There was increased substitution of affricates by fricatives for children using NLFC, compared to children using conventional amplification. After allowing for the effect of multiple demographic variables, the difference in global language scores between groups was not significant (effect: 0.8 [95% confidence interval: - 6.7, 8.3]). CONCLUSIONS: There is insufficient evidence to indicate a difference in language ability between children using NLFC and those using conventional amplification.

A randomized controlled comparison of NAL and DSL prescriptions for young children: hearing-aid characteristics and performance outcomes at three years of age.

OBJECTIVE: To determine the influence of choice of prescription and other child-, family- and intervention-related factors on speech, language, and functional performance of hearing-impaired children by three years of age. DESIGN AND STUDY SAMPLE: A randomized controlled design was implemented as part of a population-based, longitudinal study on outcomes of children with hearing impairment (LOCHI) in Australia. Two hundred and eighteen children were randomly assigned to either the NAL or the DSL prescription for first fitting of hearing aids. Their performance outcomes were evaluated. RESULTS: Prescriptive targets were closely matched in children's hearing aids. There were no significant differences in children's language, speech production, or functional performance between prescriptions. Parents' ratings of children's device usage and loudness discomfort were not significantly different between prescription groups. Functional performance within the first year of fitting together with degree of hearing loss, presence of additional disabilities, and maternal education explained 44% of variation in language ability of children by three years of age. CONCLUSIONS: There was no significant association between choice of hearing-aid prescription and variance in children's outcomes at three years of age. In contrast, additional disability, maternal educational level, and early functional performance were significant predictive factors of children's outcomes.

Audiological characteristics of children with congenital unilateral hearing loss: insights into Age of reliable behavioural audiogram acquisition and change of hearing loss.

Objectives: The aims of this study were to report the audiological characteristics of children with congenital unilateral hearing loss (UHL), examine the age at which the first reliable behavioural audiograms can be obtained, and investigate hearing changes from diagnosis at birth to the first reliable behavioural audiogram. Method: This study included a sample of 91 children who were diagnosed with UHL via newborn hearing screening and had reliable behavioural audiograms before 7 years of age. Information about diagnosis, audiological characteristics and etiology were extracted from clinical reports. Regression analysis was used to explore the potential reasons influencing the age at which first reliable behavioural audiograms were obtained. Correlation and ANOVA analyses were conducted to examine changes in hearing at octave frequencies between 0.5 and 4 kHz. The proportions of hearing loss change, as well as the clinical characteristics of children with and without progressive hearing loss, were described according to two adopted definitions: Definition 1: criterion (1): a decrease in 10 dB or greater at two or more adjacent frequencies between 0.5 and 4 kHz, or criterion (2): a decrease in 15 dB or greater at one octave frequency in the same frequency range. Definition 2: a change of ≥20 dB in the average of pure-tone thresholds at 0.5, 1, and 2 kHz. Results: The study revealed that 48 children (52.7% of the sample of 91 children) had their first reliable behavioural audiogram by 3 years of age. The mean age at the first reliable behavioural audiogram was 3.0 years (SD 1.4; IQR: 1.8, 4.1). We found a significant association between children's behaviour and the presence or absence of ongoing middle ear issues in relation to the delay in obtaining a reliable behavioural audiogram. When comparing the hearing thresholds at diagnosis with the first reliable behavioural audiogram across different frequencies, it was observed that the majority of children experienced deterioration rather than improvement in the initial impaired ear at each frequency. Notably, there were more instances of hearing changes (either deterioration or improvement), in the 500 Hz and 1,000 Hz frequency ranges compared to the 2,000 Hz and 4,000 Hz ranges. Seventy-eight percent (n = 71) of children had hearing deterioration between the diagnosis and the first behavioural audiogram at one or more frequencies between 0.5 and 4 kHz, with a high proportion of them (52 out of the 71, 73.2%) developing severe to profound hearing loss. When using the averaged three frequency thresholds (i.e., definition 2), only 26.4% of children (n = 24) in the sample were identified as having hearing deterioration. Applying definition 2 therefore underestimates the proportion of children that experienced hearing changes. The study also reported diverse characteristics of children with or without hearing deterioration. Conclusion: The finding that 78% of children diagnosed with UHL at birth had a decrease in hearing loss between the hearing levels at first diagnosis and their first behavioural audiogram highlights the importance of monitoring hearing threshold levels after diagnosis, so that appropriate intervention can be implemented in a timely manner. For clinical management, deterioration of 15 dB at one or more frequencies that does not recover warrants action.

Predicting Quality of Life and Behavior and Emotion from Functional Auditory and Pragmatic Language Abilities in 9-Year-Old Deaf and Hard-of-Hearing Children.

Children who are deaf or hard of hearing (DHH) are likely to exhibit difficulties in development of psychosocial skills, pragmatic language skills, and use of hearing for social communication in real-world environments. Some evidence suggests that pragmatic language use affects peer-relationships and school engagement in these children. However, no studies have investigated the influence of functional auditory performance and use of language and speech in real-world environments on children's behavior and emotion, and on their health-related quality of life. This study explored the relationship in DHH children at 9 years of age. Data from 144 participants of the Longitudinal Outcomes of Children with Hearing Impairment study were analyzed. Parent reports were obtained on quality of life, behavior and emotion, pragmatic language skills, and auditory functional performance of children in real life. Children's spoken language abilities and speech intelligibility were assessed by research speech pathologists. On average, performance of children in all domains was within the range of typically developing peers. There were significant associations among functional auditory performance, use of speech and language skills, psychosocial skills, and quality of life. Multiple linear regression analyses revealed that better auditory functional performance and pragmatic language skills, rather than structural language abilities, were associated with better psychosocial abilities and quality of life. The novel findings highlight the importance of targeted intervention for improving functional hearing skills and social communication abilities in DHH children, and emphasize the importance of collaborative approaches among medical, audiology, allied health, and educational professionals to identify those at risk so that timely referral and intervention can be implemented for improving psychosocial health and well-being in DHH children.

Cortical Auditory Evoked Potentials Reveal Changes in Audibility with Nonlinear Frequency Compression in Hearing Aids for Children: Clinical Implications.

Hearing loss in children is detected soon after birth via newborn hearing screening. Procedures for early hearing assessment and hearing aid fitting are well established, but methods for evaluating the effectiveness of amplification for young children are limited. One promising approach to validating hearing aid fittings is to measure cortical auditory evoked potentials (CAEPs). This article provides first a brief overview of reports on the use of CAEPs for evaluation of hearing aids. Second, a study that measured CAEPs to evaluate nonlinear frequency compression (NLFC) in hearing aids for 27 children (between 6.1 and 16.8 years old) who have mild to severe hearing loss is reported. There was no significant difference in aided sensation level or the detection of CAEPs for /g/ between NLFC on and off conditions. The activation of NLFC was associated with a significant increase in aided sensation levels for /t/ and /s/. It also was associated with an increase in detection of CAEPs for /t/ and /s/. The findings support the use of CAEPs for checking audibility provided by hearing aids. Based on the current data, a clinical protocol for using CAEPs to validate audibility with amplification is presented.

Detection Rates of Cortical Auditory Evoked Potentials at Different Sensation Levels in Infants with Sensory/Neural Hearing Loss and Auditory Neuropathy Spectrum Disorder.

With the introduction of newborn hearing screening, infants are being diagnosed with hearing loss during the first few months of life. For infants with a sensory/neural hearing loss (SNHL), the audiogram can be estimated objectively using auditory brainstem response (ABR) testing and hearing aids prescribed accordingly. However, for infants with auditory neuropathy spectrum disorder (ANSD) due to the abnormal/absent ABR waveforms, alternative measures of auditory function are needed to assess the need for amplification and evaluate whether aided benefit has been achieved. Cortical auditory evoked potentials (CAEPs) are used to assess aided benefit in infants with hearing loss; however, there is insufficient information regarding the relationship between stimulus audibility and CAEP detection rates. It is also not clear whether CAEP detection rates differ between infants with SNHL and infants with ANSD. This study involved retrospective collection of CAEP, hearing threshold, and hearing aid gain data to investigate the relationship between stimulus audibility and CAEP detection rates. The results demonstrate that increases in stimulus audibility result in an increase in detection rate. For the same range of sensation levels, there was no difference in the detection rates between infants with SNHL and ANSD.

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.

Aided cortical response, speech intelligibility, consonant perception and functional performance of young children using conventional amplification or nonlinear frequency compression.

OBJECTIVE: The aim of this study was to compare conventional processing with nonlinear frequency compression (NLFC) in hearing aids for young children with bilateral hearing loss. METHODS: Sixty-four children aged between 2 and 7 years with bilateral hearing aids were recruited. Evaluations of cortical responses, speech intelligibility rating, consonant perception and functional performance were completed with the children wearing their personal hearing aids with conventional processing. The children were then refitted with new hearing aids with NLFC processing. Following a six-week familiarization period, they were evaluated again while using their hearing aids with NLFC activated. RESULTS: The mean speech intelligibility rating and the number of cortical responses present for /s/were significantly higher when children were using NLFC processing than conventional processing in their hearing aids (p<0.05). Parents judged the children's functional real life performance with the NLFC hearing aids to be similar or better than that with the children's own hearing aids in both quiet and noisy situations. The mean percent consonant score was higher with NLFC processing compared to conventional processing, but the difference did not reach the 5% significance level (p=0.056). An overall figure of merit (FOM) was calculated by averaging the standardized difference scores between processing schemes for all measures. Regression analysis revealed that, on average, greater advantage for NLFC processing was associated with poorer hearing at 4 kHz. CONCLUSIONS: Compared to conventional processing, the use of NLFC was, on average, effective in increasing audibility of /s/as measured by cortical evaluations, and higher ratings on speech intelligibility and functional performance in real life by parents. On average, greater benefits from NLFC processing was associated with poorer hearing at 4 kHz.

Etiology and audiological outcomes at 3 years for 364 children in Australia.

Hearing loss is an etiologically heterogeneous trait with differences in the age of onset, severity and site of lesion. It is caused by a combination of genetic and/or environmental factors. A longitudinal study to examine the efficacy of early intervention for improving child outcomes is ongoing in Australia. To determine the cause of hearing loss in these children we undertook molecular testing of perinatal "Guthrie" blood spots of children whose hearing loss was either detected via newborn hearing screening or detected later in infancy. We analyzed the GJB2 and SLC26A4 genes for the presence of mutations, screened for the mitochondrial DNA (mtDNA) A1555G mutation, and screened for congenital CMV infection in DNA isolated from dried newborn blood spots. Results were obtained from 364 children. We established etiology for 60% of children. One or two known GJB2 mutations were present in 82 children. Twenty-four children had one or two known SLC26A4 mutations. GJB2 or SLC26A4 changes with unknown consequences on hearing were found in 32 children. The A1555G mutation was found in one child, and CMV infection was detected in 28 children. Auditory neuropathy spectrum disorder was confirmed in 26 children whose DNA evaluations were negative. A secondary objective was to investigate the relationship between etiology and audiological outcomes over the first 3 years of life. Regression analysis was used to investigate the relationship between hearing levels and etiology. Data analysis does not support the existence of differential effects of etiology on degree of hearing loss or on progressiveness of hearing loss.