Prelingually Deaf Children With Cochlear Implants Show Better Perception of Voice Cues and Speech in Competing Speech Than Postlingually Deaf Adults With Cochlear Implants.

OBJECTIVES: Postlingually deaf adults with cochlear implants (CIs) have difficulties with perceiving differences in speakers' voice characteristics and benefit little from voice differences for the perception of speech in competing speech. However, not much is known yet about the perception and use of voice characteristics in prelingually deaf implanted children with CIs. Unlike CI adults, most CI children became deaf during the acquisition of language. Extensive neuroplastic changes during childhood could make CI children better at using the available acoustic cues than CI adults, or the lack of exposure to a normal acoustic speech signal could make it more difficult for them to learn which acoustic cues they should attend to. This study aimed to examine to what degree CI children can perceive voice cues and benefit from voice differences for perceiving speech in competing speech, comparing their abilities to those of normal-hearing (NH) children and CI adults. DESIGN: CI children's voice cue discrimination (experiment 1), voice gender categorization (experiment 2), and benefit from target-masker voice differences for perceiving speech in competing speech (experiment 3) were examined in three experiments. The main focus was on the perception of mean fundamental frequency (F0) and vocal-tract length (VTL), the primary acoustic cues related to speakers' anatomy and perceived voice characteristics, such as voice gender. RESULTS: CI children's F0 and VTL discrimination thresholds indicated lower sensitivity to differences compared with their NH-age-equivalent peers, but their mean discrimination thresholds of 5.92 semitones (st) for F0 and 4.10 st for VTL indicated higher sensitivity than postlingually deaf CI adults with mean thresholds of 9.19 st for F0 and 7.19 st for VTL. Furthermore, CI children's perceptual weighting of F0 and VTL cues for voice gender categorization closely resembled that of their NH-age-equivalent peers, in contrast with CI adults. Finally, CI children had more difficulties in perceiving speech in competing speech than their NH-age-equivalent peers, but they performed better than CI adults. Unlike CI adults, CI children showed a benefit from target-masker voice differences in F0 and VTL, similar to NH children. CONCLUSION: Although CI children's F0 and VTL voice discrimination scores were overall lower than those of NH children, their weighting of F0 and VTL cues for voice gender categorization and their benefit from target-masker differences in F0 and VTL resembled that of NH children. Together, these results suggest that prelingually deaf implanted CI children can effectively utilize spectrotemporally degraded F0 and VTL cues for voice and speech perception, generally outperforming postlingually deaf CI adults in comparable tasks. These findings underscore the presence of F0 and VTL cues in the CI signal to a certain degree and suggest other factors contributing to the perception challenges faced by CI adults.

Cross-modal functional connectivity supports speech understanding in cochlear implant users.

Sensory deprivation can lead to cross-modal cortical changes, whereby sensory brain regions deprived of input may be recruited to perform atypical function. Enhanced cross-modal responses to visual stimuli observed in auditory cortex of postlingually deaf cochlear implant (CI) users are hypothesized to reflect increased activation of cortical language regions, but it is unclear if this cross-modal activity is "adaptive" or "mal-adaptive" for speech understanding. To determine if increased activation of language regions is correlated with better speech understanding in CI users, we assessed task-related activation and functional connectivity of auditory and visual cortices to auditory and visual speech and non-speech stimuli in CI users (n = 14) and normal-hearing listeners (n = 17) and used functional near-infrared spectroscopy to measure hemodynamic responses. We used visually presented speech and non-speech to investigate neural processes related to linguistic content and observed that CI users show beneficial cross-modal effects. Specifically, an increase in connectivity between the left auditory and visual cortices-presumed primary sites of cortical language processing-was positively correlated with CI users' abilities to understand speech in background noise. Cross-modal activity in auditory cortex of postlingually deaf CI users may reflect adaptive activity of a distributed, multimodal speech network, recruited to enhance speech understanding.

Test-Retest Reliability of the Coordinate Response Measure in Adults with Normal Hearing or Cochlear Implants.

BACKGROUND: Speech perception in noise is especially challenging for cochlear implant (CI) recipients; thus, speech in noise tests are used to clinically evaluate functional hearing with CIs. The coordinate response measure (CRM) corpus can be utilized in an adaptive speech perception test with competing speakers as the masker. Determining the critical difference for CRM thresholds can enable it to be used to evaluate changes in CI outcomes for clinical and research purposes. If a change in CRM exceeds the critical difference, then this would indicate significant improvement or decrement in speech perception. Additionally, this information provides figures for power calculations that could be used for planning studies and clinical trials [Bland JM: An Introduction to Medical Statistics, 2000]. OBJECTIVES: This study determined the test-retest reliability of the CRM for adults with normal hearing (NH) and adults with CIs. The replicability, variability, and repeatability of the CRM were evaluated for the two groups separately. METHOD: Thirty-three NH adults and thirteen adult CI recipients were recruited and tested with the CRM twice, 1 month apart. The CI group was tested with two talkers only, while the NH group was tested with seven talkers as well as two talkers. RESULTS: CRM had better replicability, repeatability and lower variability for the CI adults compared to NH adults. The critical difference (at p < 0.05) in the two-talker CRM speech reception thresholds (SRTs) among CI users was >5.2 dB, and it was >6.2 dB for the NH if an individual were to be tested under two different conditions. The critical difference (at p < 0.05) in the seven-talker CRM SRT was >6.49. The Mann-Whitney U test showed that CI recipients' CRM scores' variance (Mdn = -0.94) was significantly less than the NH group's (Mdn = 2.2) (U = 54, p < 0.0001). Although the NH had significantly better SRTs in the two-talker condition than in the seven-talker condition (t = -20.29, df = 65, p < 0.0001), the Wilcoxon signed ranks test showed no significant difference between the CRM scores' variance in the two conditions (Z = -1, N = 33, p = 0.08). CONCLUSIONS: NH adults had significantly lower CRM SRTs than the CI recipients; t (31.16) = -23.91, p < 0.001. CRM had better replicability, stability and lower variability for the CI adults compared to NH adults.

Diagnostic value of preoperative measures in selecting post-lingually deafened candidates for cochlear implantation - a different approach.

OBJECTIVES: We examined which preoperative diagnostic measure is most suited to serve as a selection criterion to determine adult cochlear implantation (CI) candidacy. DESIGN: Preoperative diagnostic measures included pure tone audiometry (PTA; 0.5, 1, 2, 4 kHz), speech perception tests (SPT) unaided with headphones and with best-aided hearing aids (in quiet and in noise). Gain in speech perception was used as outcome measure. Performance of preoperative measures was analysed using the area under the curve (AUC) of receiver operating characteristic (ROC) curves. STUDY SAMPLE: This retrospective longitudinal cohort study included 552 post-lingually deafened adults with CI in a tertiary referral centre in the Netherlands. RESULTS: Best-aided SPT in quiet was the most accurate in defining which CI candidates improved their speech perception in quiet postoperatively. For an improvement in speech perception in noise, the best-aided SPT in noise was the most accurate in defining which adult would benefit from CI. PTA measures performed lower compared to the SPT measures. CONCLUSIONS: SPT is better than PTA for selecting CI candidates who will benefit in terms of speech perception. Best-aided SPT in noise was the most accurate for indicating an improvement of speech perception in noise but was only evaluated in high performers with residual hearing. These insights will assist in formulating more effective selection criteria for CI.

Experienced hearing aid users' perspectives of assessment and communication within audiology: a qualitative study using digital methods.

OBJECTIVE: To explore experienced hearing aid users' perspectives of audiological assessments and the patient-audiologist communication dynamic during clinical interactions. DESIGN: A qualitative study was implemented incorporating both an online focus group and online semi-structured interviews. Sessions were audio-recorded and transcribed verbatim. Iterative-inductive thematic analysis was carried out to identify themes related to assessment and communication within audiology practice. STUDY SAMPLES: Seven experienced hearing aid users took part in an online focus group and 14 participated in online semi-structured interviews (age range: 22 - 86 years; 9 males, 11 females). RESULTS: Themes related to assessment included the unaided and aided testing procedure and relating tests to real world hearing difficulties. Themes related to communication included the importance of deaf aware communication strategies, explanation of test results and patient centred care in audiology. CONCLUSION: To ensure hearing aid services meet the needs of the service users, we should explore user perspectives and proactively adapt service delivery. This approach should be ongoing, in response to advances in hearing aid technology. Within audiology, experienced hearing aid users' value (1) comprehensive, relatable hearing assessment, (2) deaf aware patient-audiologist communication, (3) accessible services and (4) a personalised approach to recommend suitable technology and address patient specific aspects of hearing loss.

Selection Criteria for Cochlear Implantation in the United Kingdom and Flanders: Toward a Less Restrictive Standard.

OBJECTIVES: The impact of the newly introduced cochlear implantation criteria of the United Kingdom and Flanders (Dutch speaking part of Belgium) was examined in the patient population of a tertiary referral center in the Netherlands. We compared the patients who would be included/excluded under the new versus old criteria in relation to the actual improvement in speech understanding after implantation in our center. We also performed a sensitivity analysis to examine the effectiveness of the different preoperative assessment approaches used in the United Kingdom and Flanders. DESIGN: The selection criteria were based on preoperative pure-tone audiometry at 0.5, 1, 2, and 4 kHz and a speech perception test (SPT) with and without best-aided hearing aids. Postoperatively, the same SPT was conducted to assess the benefit in speech understanding. RESULTS: The newly introduced criteria in Flanders and the United Kingdom were less restrictive, resulting in greater percentages of patients implanted with CI (increase of 30%), and sensitivity increase of 31%. The preoperative best-aided SPT, used by both countries, had the highest diagnostic ability to indicate a postoperative improvement of speech understanding. We observed that patient selection was previously dominated by the pure-tone audiometry criteria in both countries, whereas speech understanding became more important in their new criteria. Among patients excluded by the new criteria, seven of eight (the United Kingdom and Flanders) did exhibit improved postoperative speech understanding. CONCLUSIONS: The new selection criteria of the United Kingdom and Flanders led to increased numbers of postlingually deafened adults benefitting from CI. The new British and Flemish criteria depended on the best-aided SPT with the highest diagnostic ability. Notably, the new criteria still led to the rejection of candidates who would be expected to gain considerably in speech understanding after implantation.

School-age children benefit from voice gender cue differences for the perception of speech in competing speech.

Differences in speakers' voice characteristics, such as mean fundamental frequency (F0) and vocal-tract length (VTL), that primarily define speakers' so-called perceived voice gender facilitate the perception of speech in competing speech. Perceiving speech in competing speech is particularly challenging for children, which may relate to their lower sensitivity to differences in voice characteristics than adults. This study investigated the development of the benefit from F0 and VTL differences in school-age children (4-12 years) for separating two competing speakers while tasked with comprehending one of them and also the relationship between this benefit and their corresponding voice discrimination thresholds. Children benefited from differences in F0, VTL, or both cues at all ages tested. This benefit proportionally remained the same across age, although overall accuracy continued to differ from that of adults. Additionally, children's benefit from F0 and VTL differences and their overall accuracy were not related to their discrimination thresholds. Hence, although children's voice discrimination thresholds and speech in competing speech perception abilities develop throughout the school-age years, children already show a benefit from voice gender cue differences early on. Factors other than children's discrimination thresholds seem to relate more closely to their developing speech in competing speech perception abilities.

Clinicians' views of using cortical auditory evoked potentials (CAEP) in the permanent childhood hearing impairment patient pathway.

Objective: To obtain clinicians' views on the use of cortical auditory evoked potentials (CAEP) in the clinical pathway.Design: A questionnaire aimed at clinicians who use the HEARLab system with the Aided Cortical Assessment (ACA) Module. Results compared for Australians (where HEARLab produced) to other countries.Sample: The questionnaire was completed by 49 clinicians; 33 from Australia and 13 clinicians outside of Australia and 3 clinicians, destination unknown.Results: The findings of this research demonstrated that clinicians using CAEPs found them valuable for clinical practice. CAEPs were used to verify or modify hearing aid fittings and were used for counselling parents to reinforce the need for hearing aids. With the use of speech token as the stimulus clinicians had more relevant information to increase confidence in decision-making on paediatric hearing management.Conclusions: The main benefit from the use of CAEPs (using speech token stimuli) was for infant hearing aid fitting programmes, to facilitate earlier decisions relating to hearing aid fitting, for fine-tuning the aids and as an additional measure for cochlear implant referrals.

A systematic review of the impact of adjusting input dynamic range (IDR), electrical threshold (T) level and rate of stimulation on speech perception ability in cochlear implant users.

OBJECTIVE: To systematically review the evidence of how adjustments of the electrical threshold (T) level, input dynamic range (IDR) and electrical stimulation rate impact on speech perception for cochlear implant (CI) users. DESIGN: Systematic review. STUDY SAMPLE: A search of two electronic data sources yielded 32 studies, which met the inclusion criteria. A quality assessment and two evidence-based practice (EBP) review rating schemes were used to grade studies. RESULTS: Due to the heterogeneity of speech perception measures, CI device type and study design, comparisons were made by structured review. CONCLUSION: The quality of studies was found to be moderate to poor. Increasing T levels above behavioural threshold, or as a proportion of electrical dynamic range (EDR), has been demonstrated to improve perception of monosyllables in quiet and sentences in both quiet and in noise. Specific IIDR and IDR setting may improve perception of monosyllables in quiet and sentences in noise. However, no recommendation could be determined for setting rate of stimulation as speech perception varied significantly across rates examined. To optimise speech perception, a bespoke approach to parameter setting providing an individualised CI fitting is recommended; however, detail of how to optimise settings and the interactions between parameters is as yet unknown.

Closed-Set Speech Discrimination Tests for Assessing Young Children.

OBJECTIVE: The main objective of this study is to obtain data assessing normative scores, test-retest reliability, critical differences, and the effect of age for two closed-set consonant-discrimination tests. DESIGN: The two tests are intended for use with children aged 2 to 8 years. The tests were evaluated using normal-hearing children within the appropriate age range. The tests were (1) the closed-set consonant confusion test (CCT) and (2) the consonant-discrimination subtest of the closed-set Chear Auditory Perception Test (CAPT). Both were word-identification tests using stimuli presented at a low fixed level, chosen to avoid ceiling effects while avoiding the use of background noise. Each test was administered twice. RESULTS: All children in the age range 3 years 2 months to 8 years 11 months gave meaningful scores and were able to respond reliably using a computer mouse or a touch screen to select one of four response options displayed on a screen for each trial. Assessment of test-retest reliability showed strong agreement between the two test runs (interclass correlation ≥ 0.8 for both tests). The critical differences were similar to those for other monosyllabic speech tests. Tables of these differences for the CCT and CAPT are provided for clinical use of the measures. Performance tended to improve with increasing age, especially for the CCT. Regression equations relating mean performance to age are given. CONCLUSIONS: The CCT is appropriate for children with developmental age in the range 2 to 4.5 years and the CAPT is appropriate as a follow-on test from the CCT. If a child scores 80% or more on the CCT, they can be further tested using the CAPT, which contains more advanced vocabulary and more difficult contrasts. This allows the assessment of consonant perception ability and of changes over time or after an intervention.

Comparison of Different Hearing Aid Prescriptions for Children.

OBJECTIVES: To assess whether there are significant differences between speech scores for different hearing aid prescription methods, specifically DSL i/o, DSL V, and NAL-NL1, using age-appropriate closed- and open-set speech tests with young children, designed to avoid floor and ceiling effects. DESIGN: Participants were 44 children with moderate or severe bilateral hearing loss, 8 aged 2 to 3 years, 15 aged 4 to 5 years, and 21 aged 6 to 9 years. Children wore bilateral hearing aids fitted with each prescription method in turn in a balanced double-blind design. The speech tests used with each child (and for some tests the levels) were chosen so as to avoid floor and ceiling effects. For the closed-set tests, the level used was selected for each child based on their hearing loss. The tests used were: (1) The closed-set Consonant Confusion Test of word identification; (2) The closed-set Chear Auditory Perception Test (CAPT) of word identification. This has separate sections assessing discrimination of consonants and vowels and detection of consonants; (3) The open-set Cambridge Auditory Word Lists for testing word identification at levels of 50 and 65 dBA, utilizing 10 consonant-vowel-consonant real words that are likely to be familiar to children aged 3 years or older; (4) The open-set Common Phrases Test to measure the speech reception threshold in quiet; (5) Measurement of the levels required for identification of the Ling 5 sounds, using a recording of the sounds made at the University of Western Ontario. RESULTS: Scores for the Consonant Confusion Test and CAPT consonant discrimination and consonant detection were lower for the NAL-NL1 prescription than for the DSL prescriptions. Scores for the CAPT vowel-in-noise discrimination test were higher for DSL V than for either of the other prescriptions. Scores for the Cambridge Auditory Word Lists did not differ across prescriptions for the level of 65 dBA, but were lower for the NAL-NL1 prescription than for either of the DSL prescriptions for the level of 50 dBA. The speech reception threshold measured using the Common Phrases Test and the levels required for identification of the Ling 5 sounds were higher (worse) for the NAL-NL1 prescription than for the DSL prescriptions. CONCLUSIONS: The higher gains prescribed by the DSL i/o and DSL V prescription methods relative to NAL-NL1 led to significantly better detection and discrimination of low-level speech sounds.

Assessment and Outcome in Non-Traditional Cochlear Implant Candidates.

The objectives of this study were to assess: (i) patient expectations met as a measure of outcome in early-deafened, late-implanted (non-traditional) cochlear implant recipients and (ii) pre-implantation predictive factors for postoperative speech perception. The notes of 13 recipients were retrospectively reviewed. The mean age at onset of profound deafness was 1.5 years (range 0-6). The mean age at implantation was 37 years (range 22-51 years). Patient expectations were assessed pre-operatively and 1 year after implantation. They were met or exceeded in 129/140 (92%) domains overall. A higher Speech Intelligibility Rating and audiovisual City University of New York sentence score before implantation were found to be positive predictive factors for improved speech discrimination after cochlear implantation.

Deactivating Cochlear Implant Electrodes Based on Pitch Information for Users of the ACE Strategy.

There is a wide range in performance for cochlear implant (CI) users and there is some evidence to suggest that implant fitting can be modified to improve performance if electrodes that do not provide distinct pitch information are de-activated. However, improvements in performance may not be the same for users of all CI devices; in particular for those with Cochlear devices using n-of-m strategies (ACE or SPEAK).The goal of this research was to determine for users of Cochlear devices (CP810 or CP900 series processors) if speech perception could be improved when indiscriminable electrodes were de-activated and this was also compared to when the same number of discriminable electrodes were de-activated.A cross-over study was conducted with 13 adult CI users who received experimental maps with de-activated channels for a minimum of 2 months and these were compared to optimised clinical maps.The findings showed that there were no significant benefits of electrode de-activation on speech perception and that there was a significant deterioration in spectro-temporal ripple perception when electrodes were switched off. There were no significant differences between de-activation of discriminable or indiscriminable electrodes.These findings suggest that electrode de-activation with n-of-m strategies may not be beneficial.

Bilateral cochlear implantation for hearing-impaired children: criterion of candidacy derived from an observational study.

OBJECTIVES: Policy-makers have struggled to define the minimum degree of hearing impairment at which children should be offered cochlear implants rather than the less invasive alternative of acoustic hearing aids. This study compared outcomes for children with bilateral cochlear implants and children with bilateral hearing aids, to determine a criterion of candidacy for pediatric bilateral cochlear implantation. DESIGN: This observational study measured the listening skills of children who received routine audiological care in the United Kingdom. Participants were recruited from hospitals, educational services, and charities. Eligibility criteria included a diagnosis of hearing impairment before 31 months of age and pure-tone thresholds greater than or equal to 50 dB HL at 2 and 4 kHz bilaterally. Seventy-one children participated, aged 46 to 86 months (mean 64 months). Twenty-eight children used bilateral implants provided in a simultaneous surgery; 43 used bilateral digital hearing aids. The two groups of children were demographically similar in variables that predict outcomes for children with hearing impairment. Children's ability to understand speech was measured using closed-set tests of word discrimination in three conditions: in quiet, in pink noise, and in two-talker babble. For each listening test, an actuarial method was used to compare the distribution of scores from children with cochlear implants and children with hearing aids. The aim was to calculate the unaided pure-tone average (PTA) hearing level at which a child has odds of 4:1 of a better outcome with implants than with hearing aids. The PTA associated with odds of 4:1 has been used previously to define criteria of candidacy for implantation. The main analyses used a four-frequency PTA (mean of unaided thresholds at 0.5, 1, 2, and 4 kHz in the better-hearing ear). Additional analyses used a three-frequency PTA (0.5, 1, and 2 kHz) and two-frequency PTA (2 and 4 kHz). RESULTS: Odds of 4:1 of a better outcome with implants were associated with a four-frequency PTA of 79, 86, and 76 dB HL for tests of word discrimination in quiet, noise, and babble, respectively. The mean of these three estimates is 80 dB HL. It can be difficult to measure a four-frequency PTA in young children, but a two-frequency PTA typically can be measured. Odds of 4:1 were associated with a two-frequency PTA of 83, 92, and 80 dB HL for tests of word discrimination in quiet, noise, and babble, respectively. The mean of these three estimates is 85 dB HL. CONCLUSIONS: Children with an unaided four-frequency PTA of 80 dB HL or poorer in both ears should be considered candidates for bilateral cochlear implantation. In cases where a four-frequency PTA cannot be measured, the criterion of candidacy should be a two-frequency PTA of 85 dB HL or poorer in both ears. If adopted by policy-makers, these recommendations would expand the provision of cochlear implants among children in England and Wales.

Mobile telephone use effects on perception of verticality.

Low-level radiofrequency (RF) signals may produce disorientation and nausea. In experiment I, we assessed mobile phone effects on graviception in nine symptomatic subjects after mobile telephone use and 21 controls. The mobile handset was strapped to each ear for 30 min in pulsed emission, continuous RF emission, or no emission test mode, respectively. The subjective visual vertical and horizontal (SVV/SVH) were tested from min 25 of exposure. There was no exposure effect; however, there was an ear effect, with the SVV/SVH being shifted to the opposite direction of the ear exposed. This could be due to thermal or RF effects or handset weight. In experiment II, we assessed the handset weight effect on 18 normal controls. After baseline SVV/SVH, the switched off handset was strapped to either ear; the SVV/SVH was repeated 25 min later. A significant ear effect was found. We compared the observed ear effect SVV/SVH change in the experiment II group to the continuous exposure ear effect change in the experiment I group, and the difference was not significant. The ear effect was attributed to a minor head tilt due to the handset weight, or proprioceptive stimulation of neck muscle affecting the perception of verticality.

Developing an assessment approach for perceptual changes to tinnitus sound characteristics for adult cochlear implant recipients.

OBJECTIVE: To investigate the impact of cochlear implantation on tinnitus suppression, characteristics, localization, and duration. DESIGN: A cochlear implant (CI) recipient-focused postal questionnaire survey. STUDY SAMPLE: The questionnaire was posted, with consent, to 100 adults who had received a unilateral CI at the RNTNEH between 1988 and 1999. All adults spoke English as their first language and were postlingually deafened. Sixty-eight adults (38 female, 29 male, one unspecified) aged 31-80 years (mean 61 years) completed and returned the questionnaire without interview. RESULTS: With the processor 'ON', CI recipients experienced total or partial suppression of tinnitus ipsilateral to their CI in 57% of cases, and in 43% where tinnitus was perceived contralateral to the CI. The percentage of CI recipients who experienced high tone tinnitus was reduced from 60% pre-implant to 29% post-implant with the processor 'ON' while pulsatile tinnitus was reduced from 38% pre-implant to 13% post-implant. CIs were also found to reduce the tonal complexity and duration, and change the source localization of tinnitus post-implantation. CONCLUSIONS: Perceptual changes to tinnitus can take place post-implantation. Changes can occur within the four categories explored: tinnitus suppression, characteristics, localization, and duration of awareness per day.

Rate dependent neural responses of interaural-time-difference cues in fine-structure and envelope.

Advancements in cochlear implants (CIs) have led to a significant increase in bilateral CI users, especially among children. Yet, most bilateral CI users do not fully achieve the intended binaural benefit due to potential limitations in signal processing and/or surgical implant positioning. One crucial auditory cue that normal hearing (NH) listeners can benefit from is the interaural time difference (ITD), i.e., the time difference between the arrival of a sound at two ears. The ITD sensitivity is thought to be heavily relying on the effective utilization of temporal fine structure (very rapid oscillations in sound). Unfortunately, most current CIs do not transmit such true fine structure. Nevertheless, bilateral CI users have demonstrated sensitivity to ITD cues delivered through envelope or interaural pulse time differences, i.e., the time gap between the pulses delivered to the two implants. However, their ITD sensitivity is significantly poorer compared to NH individuals, and it further degrades at higher CI stimulation rates, especially when the rate exceeds 300 pulse per second. The overall purpose of this research thread is to improve spatial hearing abilities in bilateral CI users. This study aims to develop electroencephalography (EEG) paradigms that can be used with clinical settings to assess and optimize the delivery of ITD cues, which are crucial for spatial hearing in everyday life. The research objective of this article was to determine the effect of CI stimulation pulse rate on the ITD sensitivity, and to characterize the rate-dependent degradation in ITD perception using EEG measures. To develop protocols for bilateral CI studies, EEG responses were obtained from NH listeners using sinusoidal-amplitude-modulated (SAM) tones and filtered clicks with changes in either fine structure ITD (ITDFS) or envelope ITD (ITDENV). Multiple EEG responses were analyzed, which included the subcortical auditory steady-state responses (ASSRs) and cortical auditory evoked potentials (CAEPs) elicited by stimuli onset, offset, and changes. Results indicated that acoustic change complex (ACC) responses elicited by ITDENV changes were significantly smaller or absent compared to those elicited by ITDFS changes. The ACC morphologies evoked by ITDFS changes were similar to onset and offset CAEPs, although the peak latencies were longest for ACC responses and shortest for offset CAEPs. The high-frequency stimuli clearly elicited subcortical ASSRs, but smaller than those evoked by lower carrier frequency SAM tones. The 40-Hz ASSRs decreased with increasing carrier frequencies. Filtered clicks elicited larger ASSRs compared to high-frequency SAM tones, with the order being 40 > 160 > 80> 320 Hz ASSR for both stimulus types. Wavelet analysis revealed a clear interaction between detectable transient CAEPs and 40-Hz ASSRs in the time-frequency domain for SAM tones with a low carrier frequency.

Protocol for a multicentre randomised controlled trial of STeroid Administration Routes For Idiopathic Sudden sensorineural Hearing loss: The STARFISH trial.

Idiopathic sudden sensorineural hearing loss (ISSNHL) is the rapid onset of reduced hearing due to loss of function of the inner ear or hearing nerve of unknown aetiology. Evidence supports improved hearing recovery with early steroid treatment, via oral, intravenous, intratympanic or a combination of routes. The STARFISH trial aims to identify the most clinically and cost-effective route of administration of steroids as first-line treatment for ISSNHL. STARFISH is a pragmatic, multicentre, assessor-blinded, three-arm intervention, superiority randomised controlled trial (1:1:1) with an internal pilot (ISRCTN10535105, IRAS 1004878). 525 participants with ISSNHL will be recruited from approximately 75 UK Ear, Nose and Throat units. STARFISH will recruit adults with sensorineural hearing loss averaging 30dBHL or greater across three contiguous frequencies (confirmed via pure tone audiogram), with onset over a ≤3-day period, within four weeks of randomisation. Participants will be randomised to 1) oral prednisolone 1mg/Kg/day up to 60mg/day for 7 days; 2) intratympanic dexamethasone: three intratympanic injections 3.3mg/ml or 3.8mg/ml spaced 7±2 days apart; or 3) combined oral and intratympanic steroids. The primary outcome will be absolute improvement in pure tone audiogram average at 12-weeks following randomisation (0.5, 1.0, 2.0 and 4.0kHz). Secondary outcomes at 6 and 12 weeks will include: Speech, Spatial and Qualities of hearing scale, high frequency pure tone average thresholds (4.0, 6.0 and 8.0kHz), Arthur Boothroyd speech test, Vestibular Rehabilitation Benefit Questionnaire, Tinnitus Functional Index, adverse events and optional weekly online speech and pure tone hearing tests. A health economic assessment will be performed, and presented in terms of incremental cost effectiveness ratios, and cost per quality-adjusted life-year. Primary analyses will be by intention-to-treat. Oral prednisolone will be the reference. For the primary outcome, the difference between group means and 97.5% confidence intervals at each time-point will be estimated via a repeated measures mixed-effects linear regression model.

Using personal response systems to assess speech perception within the classroom: an approach to determine the efficacy of sound field amplification in primary school classrooms.

OBJECTIVES: The assessment of the combined effect of classroom acoustics and sound field amplification (SFA) on children's speech perception within the "live" classroom poses a challenge to researchers. The goals of this study were to determine: (1) Whether personal response system (PRS) hand-held voting cards, together with a closed-set speech perception test (Chear Auditory Perception Test [CAPT]), provide an appropriate method for evaluating speech perception in the classroom; (2) Whether SFA provides better access to the teacher's speech than without SFA for children, taking into account vocabulary age, middle ear dysfunction or ear-canal wax, and home language. DESIGN: Forty-four children from two school-year groups, year 2 (aged 6 years 11 months to 7 years 10 months) and year 3 (aged 7 years 11 months to 8 years 10 months) were tested in two classrooms, using a shortened version of the four-alternative consonant discrimination section of the CAPT. All children used a PRS to register their chosen response, which they selected from four options displayed on the interactive whiteboard. The classrooms were located in a 19th-century school in central London, United Kingdom. Each child sat at their usual position in the room while target speech stimuli were presented either in quiet or in noise. The target speech was presented from the front of the classroom at 65 dBA (calibrated at 1 m) and the presented noise level was 46 dBA measured at the center of the classroom. The older children had an additional noise condition with a noise level of 52 dBA. All conditions were presented twice, once with SFA and once without SFA and the order of testing was randomized. White noise from the teacher's right-hand side of the classroom and International Speech Test Signal from the teacher's left-hand side were used, and the noises were matched at the center point of the classroom (10sec averaging [A-weighted]). Each child's expressive vocabulary age and middle ear status were measured individually and each child's home language and any special educational needs were recorded. RESULTS: All children were able to use the PRS handsets, and the CAPT speech perception test was sufficiently sensitive to highlight differences in perception in the different listening conditions. Scores were higher in quiet than in any noise condition. Results showed that group performance was significantly better with SFA than without it. The main demographic predictor of performance was expressive vocabulary age. SFA gave more benefit to the poorer performers in the group. There were no significant effects on performance relating to middle ear status or home language; however, the size of the population was too small to be able to fully explore these aspects in greater detail. CONCLUSION: PRS together with the CAPT provides a sensitive measure for in situ speech perception testing within the classroom. Vocabulary age has a large effect on a child's ability to perceive the speech signal. SFA leads to improved speech perception, when the speech signal has been degraded because of poor acoustics or background noise and has a particularly large effect for children with lower vocabulary ages.

Test-retest reliability of the Toy Discrimination Test with a masker of noise or babble in children with hearing impairment.

OBJECTIVE: The Toy Discrimination Test measures children's ability to discriminate spoken words. Previous assessments of reliability tested children with normal hearing or mild hearing impairment, and most studies used a version of the test without a masking sound. We assessed test-retest reliability for children with hearing impairment using maskers of broadband noise and two-talker babble. DESIGN: Stimuli were presented from a loudspeaker. The signal-to-noise ratio (SNR) was varied adaptively to estimate the speech-reception threshold (SRT) corresponding to 70.7% correct performance. Participants completed each masked condition twice. STUDY SAMPLE: Fifty-five children with permanent hearing impairment participated, aged 3.0 to 6.3 years. Thirty-four children used acoustic hearing aids; 21 children used cochlear implants. RESULTS: For the noise masker, the within-subject standard deviation of SRTs was 2.4 dB, and the correlation between first and second SRT was + 0.73. For the babble masker, corresponding values were 2.7 dB and + 0.60. Reliability was similar for children with hearing aids and children with cochlear implants. CONCLUSIONS: The results can inform the interpretation of scores from individual children. If a child completes a condition twice in different listening situations (e.g. aided and unaided), a difference between scores ≥ 7.5 dB would be statistically significant (p <.05).