Speech Perception In Quiet Research Articles

Temporal processing and speech perception in quiet and noise across different degrees of ANSD

Objective: The aim of the present study was to examine the effect of degree of temporal processing impairment in adult listeners with ANSD on speech perception measures. Study design: Forty-six listeners with ANSD and 30 normal hearing listeners participated in the study. Temporal resolution was measured using the Temporal Modulation Transfer Function (TMTF). Speech identification scores in quiet were measured for bisyllabic words and Speech Reception Threshold in noise (SRTn) was measured for words. Furthermore, consonant identification was measured for 20 VCV stimuli. Results: Listeners with ANSD performed significantly worse than normal hearing listeners in both temporal resolution and speech perception measures. Peak sensitivity and 3dB cut-off frequency were estimated for each individual in both groups from the TMTFs data using an exponential fitting function. The listeners with ANSD were subgrouped into mild, moderate and severe degrees based on peak sensitivity. As the degree of temporal processing impairment increased, speech identification scores reduced and SRTn increased systematically. Similarly, consonant identification decreased with increase in temporal processing impairment. Among phonemic features, manner of articulation was better perceived compared to voice and place of articulation. Conclusion: The high correlation between temporal processing ability and speech perception suggests that temporal processing measures may be a potential tool for assessing the severity of ANSD in adult listeners.

Assessing speech perception in children with hearing loss: what conventional clinical tools may miss.

This study tested the hypothesis that word recognition in a complex, two-talker masker is more closely related to real-world speech perception for children with hearing loss than testing performed in quiet or steady-state noise. Sixteen school-age hearing aid users were tested on aided word recognition in noise or two-talker speech. Unaided estimates of speech perception in quiet were retrospectively obtained from the clinical record. Ten parents completed a questionnaire regarding their children's ease of communication and understanding in background noise. Unaided performance in quiet was correlated with aided performance in competing noise, but not in two-talker speech. Only results in the two-talker masker were correlated with parental reports of their children's functional hearing abilities. Speech perception testing in a complex background such as two-talker speech may provide a more accurate predictor of the communication challenges of children with hearing loss than testing in steady noise or quiet.

Predictive Factors of Cochlear Implant Outcomes in the Elderly

Objective: To analyze predictive factors of cochlear implant outcomes and postoperative complications in the elderly. Study Design: Prospective, longitudinal study performed in 10 tertiary referral centers. Methods: Ninety-four patients aged 65-85 years with a profound, postlingual hearing loss were evaluated before implantation, at time of activation, and 6 and 12 months after cochlear implantation. Speech perception and lipreading were measured using disyllabic word recognition in quiet and noise, and lipreading using disyllabic words and sentences. The influence of preoperative factors on speech perception in quiet and noise at 12 months was tested in a multivariate analysis. Complications, presence of tinnitus and of vestibular symptoms were collected at each evaluation. Results: The effect of age was observed only in difficult noisy conditions at SNR 0 dB. Lipreading ability for words and sentences was negatively correlated with speech perception in quiet and noise. Better speech perception scores were observed in patients with shorter duration of hearing deprivation, persistence of residual hearing for the low frequencies, the use of a hearing aid before implantation, the absence of cardiovascular risk factors, and in those with implantation in the right ear. General and surgical complications were very rare, and the percentage of vestibular symptoms remained stable over time. Conclusion:This study demonstrates that cochlear implantation in the elderly is a well-tolerated procedure and an effective method to improve communication ability. Advanced age has a low effect on cochlear implant outcome. Analyses of predictive factors in this population provide a convincing argument to recommend treatment with cochlear implantation as early as possible in elderly patients with confirmed diagnosis of a severe-to-profound hearing loss and with only limited benefit from hearing aid use in one ear.

Amplification for listeners with a moderately severe high-frequency hearing loss.

Some evidence exists to support the use of an extended bandwidth (EBW) for those with a relatively mild to moderate degree of hearing loss. The use of frequency lowering is suggested for those with a severe/profound degree of hearing loss. The amplification option for those with a moderately severe hearing loss in the high frequencies is less clear. This study compared three amplification options for listeners with a moderately severe hearing loss in the high frequencies. The efficacy of three amplification options-limited bandwidth to 4000 Hz, EBW, and frequency transposition-were evaluated for listeners with a moderately severe, high-frequency hearing loss. The experiment used a factorial repeated-measures design. A total of 13 adults with bilateral hearing loss of 50-70 dB HL at 4000 Hz served as test participants. The participants rated the sound quality of birdsongs and music when aided with the amplification options. Speech perception in quiet was measured at 50 dB SPL and 68 dB SPL input levels. The participants also completed a questionnaire on the best amplification option to use in different real-life environments during a 2 wk, take-home trial. The data were analyzed with repeated-measures analysis of variance. The findings showed that more listeners preferred the EBW for home use but that the frequency transposition was the least preferred. In addition, the performance of the EBW was better than that of the limited bandwidth in speech recognition but similar to that of the frequency transposition. The results supported the fitting of an EBW as the better choice for this group of listeners.

Hearing loss and auditory processing ability in people with aphasia

Background: Hearing loss can add to the linguistic deficits present in aphasia to make comprehension of speech difficult. Although some studies document a relatively high prevalence of hearing loss in adults with aphasia, many people with aphasia do not have their hearing tested. Self-reported disability measures offer a possible alternative to pure-tone audiometry when this service is not readily available.Aims: This study aims to investigate the prevalence of hearing loss in a group of people with aphasia and to determine the usefulness of self-reported measures to screen for hearing impairment.Methods & Procedures: Hearing ability was measured using pure-tone audiometry and five measures of auditory processing, which looked at speech perception in quiet and noise, for 21 individuals with aphasia recruited from a community clinic and 21 age-matched individuals without aphasia. The Speech, Spatial and Qualities of Hearing Scale (SSQ) and a brief questionnaire exploring whether they had experienced hearing difficulties were used to measure self-perception of hearing acuity. Differences in scores between the groups were analysed. Correlations and regressions were used to establish the relationship between self-perception of hearing and measures of hearing ability.Outcomes & Results: Despite minimal impairment and a non-significant difference between performance on pure-tone audiometry for participants with and without aphasia, participants with aphasia performed significantly worse on measures of speech perception in noise than participants without aphasia. They also had a significantly greater degree of perceived hearing disability. Although SSQ scores were correlated with some behavioural measures for the participants with aphasia, the SSQ only predicted the hearing status and speech in noise performance of control participants.Conclusions: The results suggest that the prevalence of hearing loss for people with aphasia (at least for this group) is no greater than the general population. However, they are significantly more affected in their recognition of speech in noise and experience greater disability in listening situations than people without aphasia. The latter problems were not predicted by pure-tone audiograms or sound-in-noise performance. The brief questionnaire was not effective in identifying hearing impairment, indicating the need for a regular hearing screen to ensure provision of the most effective rehabilitation. Ideally, the screen should include disability and behavioural measures, as our results suggest they cannot replace each other. These findings should assist clinicians in setting realistic goals and delivering interventions in the most effective way for people with aphasia.

Effects of ageing and hearing thresholds on speech perception in quiet and in noise perceived in different locations.

Background and ObjectivesThis study investigated the effect of ageing on speech perception in quiet and in noise, with noise directed from front, right and left.Subjects and MethodsSixty Malay native adults with normal or near normal hearing comprising of 20 young adults (21 to 39 years old), 20 middle aged (40 to 59 years old) and 20 older adults (60 to 74 years old) participated in this study. Their speech perception ability was measured using the Malay Hearing in Noise Test (HINT) in four test conditions; 1) in quiet (HINT Q), 2) with noise from front (HINT NF), 3) with noise from right (HINT NR), and 4) with noise from left (HINT NL). Reception thresholds for sentences (RTSs) were measured in each of the aforementioned conditions using an adaptive method.ResultsThe results showed that, 1) genuine age-related decline was found in speech perception performance in HINT (NF), 2) hearing threshold was a major determinant differentiating speech perception performance for HINT (Q) and HINT (NL) conditions, and 3) speech perception performance for HINT (NR) was determined by both age and hearing threshold.ConclusionsThis study suggests that, in older adults, while hearing thresholds affect speech perception in quiet, other factors such as central auditory processing and cognitive functions might be more important determinant factors for speech perception performance in noise.

Children’s Recognition of Spectrally Degraded Cartoon Voices

Although the spectrally degraded input provided by cochlear implants (CIs) is sufficient for speech perception in quiet, it poses problems for talker identification. The present study examined the ability of normally hearing (NH) children and child CI users to recognize cartoon voices while listening to spectrally degraded speech. In Experiment 1, 5- to 6-year-old NH children were required to identify familiar cartoon characters in a three-alternative, forced-choice task without feedback. Children heard sentence-length utterances at six levels of spectral degradation (noise-vocoded utterances with 4, 8, 12, 16, and 24 frequency bands and the original or unprocessed stimuli). In Experiment 2, child CI users 4 to 7 years of age and a control sample of 4- to 5-year-old NH children were required to identify the unprocessed stimuli from Experiment 1. NH children in Experiment 1 identified the voices significantly above chance levels, and they performed more accurately with increasing spectral information. Practice with stimuli that had greater spectral information facilitated performance on subsequent stimuli with lesser spectral information. In Experiment 2, child CI users successfully recognized the cartoon voices with slightly lower accuracy (0.90 proportion correct) than NH peers who listened to unprocessed utterances (0.97 proportion correct). The findings indicate that both NH children and child CI users can identify cartoon voices under conditions of severe spectral degradation. In such circumstances, children may rely on talker-specific phonetic detail to distinguish one talker from another.

Effect of companding on speech recognition in quiet and noise for listeners with ANSD

Objective: The present study assesses the effect of companding on speech perception in quiet and noise for listeners with auditory neuropathy spectrum disorder (ANSD). Design: Speech perception was assessed using speech reception threshold in noise (SRTn) for sentences and consonant identification in quiet and at different signal-to-noise ratios (15, 10, 5, and 0 dB SNR). Study sample: Ten ANSD listeners and normal-hearing listeners participated in the study. Results: ANSD listeners required significantly higher SRTn when compared to the normal-hearing listeners. Companding reduced SRTn more significantly in listeners with ANSD, but for normal-hearing listeners there was only a marginal reduction. In the consonant identification task, ANSD listeners performed poorer than normal-hearing listeners in quiet and noise. Companding improved consonant identification in quiet and at 15 dB SNR for listeners with ANSD, whereas no improvement was observed in normal-hearing listeners. Conclusion: Results of the present study demonstrate that companding improved speech perception in quiet and noise for ANSD listeners. The amount of improvement is higher at higher SNRs. In normal-hearing listeners, companding showed marginal improvement in both quiet and noise. The findings are discussed for rehabilitation of ANSD listeners by hearing aids which incorporate the companding strategy.

Xylene-Induced Auditory Dysfunction in Humans

Animal data indicate that xylene induces cochlear dysfunction, characterized by the loss of outer hair cells. There is little evidence regarding xylene-induced ototoxicity in humans. The aim of the study was to investigate the possible adverse effects of xylene on the peripheral and central auditory system in humans. A total of 30 medical laboratory workers who had been exposed to a mixture of xylene isomers, together with 30 nonexposed control participants matched for gender, age, and educational level were selected. Participants of both groups were not exposed to noise levels above 85 dBA time-weighted average. All participants were evaluated with a comprehensive audiological test battery, which included measures of peripheral and central auditory function. Peripheral auditory measures included pure-tone audiometry and distortion product otoacoustic emissions. Behavioral measures of central auditory function included a pitch pattern sequence test, an adaptive test of temporal resolution, a dichotic digit test, and a masking level difference test. The auditory brainstem response was used to objectively evaluate the function of the auditory pathways at the brainstem level. Speech perception in quiet and in noise was evaluated using the Hearing In Noise Test (HINT). The xylene-exposed participants were extensively evaluated with regard to their exposure to both noise and xylene. Noise dosimetry was conducted over an 8-hr work shift to obtain noise-exposure levels for each xylene-exposed worker. Airborne xylene concentrations were obtained at 11 different workstations throughout the medical laboratories, and methyl hippuric acid levels per gram of creatinine in urine were obtained for each xylene-exposed subject. Finally, a detailed interview exploring current and past solvent and noise exposure was conducted. The xylene-exposed participants showed significantly worse pure-tone thresholds in comparison with the nonexposed participants. The xylene-exposed participants demonstrated significantly worse results than the control group participants for the pitch pattern sequence test, dichotic digit test, HINT, and the auditory brainstem response (absolute and interpeak latencies). No significant differences between the xylene-exposed and nonexposed participants were observed for distortion product otoacoustic emissions, adaptive test of temporal resolution, or the masking level difference test. A significant correlation between the concentrations of methyl hippuric acid in urine and pure-tone thresholds (2 to 8 kHz) was found in xylene-exposed workers. Also, participants with high cumulative dose of xylene exposure presented with poorer test results than participants with low cumulative dose of xylene exposure. The results of the present research suggest that xylene is associated with adverse central auditory effects and poorer sound detection abilities in humans. A major limitation of the study is that the results found among xylene-exposed participants cannot be proved to be permanent, and thus further research should be conducted to clarify this limitation. Workers exposed to this chemical should be routinely evaluated with a comprehensive audiological test battery, to detect early signs of auditory dysfunction.

Cognitive Abilities Relate to Self-Reported Hearing Disability

In this explorative study, the authors investigated the relationship between auditory and cognitive abilities and self-reported hearing disability. Thirty-two adults with mild to moderate hearing loss completed the Amsterdam Inventory for Auditory Disability and Handicap (AIADH; Kramer, Kapteyn, Festen, & Tobi, 1996) and performed the Text Reception Threshold (TRT; Zekveld, George, Kramer, Goverts, & Houtgast, 2007) test as well as tests of spatial working memory (SWM) and visual sustained attention. Regression analyses examined the predictive value of age, hearing thresholds (pure-tone averages [PTAs]), speech perception in noise (speech reception thresholds in noise [SRTNs]), and the cognitive tests for the 5 AIADH factors. Besides the variance explained by age, PTA, and SRTN, cognitive abilities were related to each hearing factor. The reported difficulties with sound detection and speech perception in quiet were less severe for participants with higher age, lower PTAs, and better TRTs. Fewer sound localization and speech perception in noise problems were reported by participants with better SRTNs and smaller SWM. Fewer sound discrimination difficulties were reported by subjects with better SRTNs and TRTs and smaller SWM. The results suggest a general role of the ability to read partly masked text in subjective hearing. Large working memory was associated with more reported hearing difficulties. This study shows that besides auditory variables and age, cognitive abilities are related to self-reported hearing disability.

Evaluation of a New Powerful Bone-Anchored Hearing System: A Comparison Study

The recent introduction of digital hearing aid technology for bone-conduction devices employing percutaneous stimulation may be beneficial for patients with conductive and mixed hearing loss and single sided deafness. Performance of a recently released sound processor for bone-anchored implants, the Ponto Pro Power from Oticon Medical (bone-conduction device 2 [BCD2]), was compared with that of the Baha Intenso from Cochlear (bone-conduction device 1 [BCD1]). Direct comparison of the subject's own device (BCD1) with the new device (BCD2) was examined in a nonrandomized design. Subjects were initially tested with BCD1. BCD2 was tested after a 4 wk acclimatization period. Eighteen subjects with mixed hearing loss and with at least 4 mo experience with BCD1 completed the study. Mean air-conduction and bone-conduction thresholds averaged across the frequencies of 500, 1000, 2000, and 4000 Hz were 73.9 and 34.2 dB HL, respectively. Performance of the two devices was evaluated objectively by measuring aided free-field thresholds, speech perception in quiet, and speech perception in noise. A subjective evaluation was carried out with the Abbreviated Profile of Hearing Aid Benefit (APHAB) (Cox and Alexander, 1995) and the Speech, Spatial and Qualities of Hearing Scale (SSQ) questionnaire (Gatehouse and Noble, 2004). In addition, user experiences, user satisfaction, and device preference were obtained via proprietary questionnaires. Statistical significance was established with analysis-of-variance (ANOVA) and paired t-statistics with Bonferroni correction. Aided free-field thresholds and speech reception thresholds (SRTs) in quiet were not statistically significantly different for either device (p > 0.05). In contrast, SRTs in noise were 2.0 dB lower (p < 0.001) for BCD2 than for BCD1. APHAB questionnaire scores on all subscales provided statistically significantly greater benefit (p < 0.05) for BCD2 than for BCD1. Also, with the SSQ most items in the speech and sound quality domain were significantly more favorable (p < 0.05) for BCD2 than for BCD1. Finally, all subjects preferred BCD2 over BCD1 with 14 subjects reporting a strong preference and four subjects an average preference for the digital signal processing provided by BCD2 over previous technology provided by BCD1.

Comparison of Sound Processing Strategies for Osseointegrated Bone Conduction Implants in Mixed Hearing Loss

Evaluation of a single-channel linear bone conduction implant sound processor (S-BCI) and a multiple-channel nonlinear bone conduction implant sound processor (M-BCI) with objective and subjective measures in patients with mixed hearing loss. In total, 20 patients with mixed hearing loss were included in the study. For either sound processor aided thresholds and speech perception in quiet with monosyllables were measured. Speech perception in noise was measured with sentences. Two different configurations were used: speech and noise at 0° (S0N0) and speech at 0° and noise at 180° (S0N180). The M-BCI was tested in both omnidirectional and directional mode. Patients were first fitted with the S-BCI and evaluated 3 weeks later. The M-BCI was fitted and, again 3 weeks later, evaluated. Subjectively, patients compared both sound processors with the APHAB questionnaire. Aided thresholds were similar for both sound processors in the low- and mid-frequency range. For speech in quiet, no significant differences between both sound processors were observed. For speech in noise in the S0N0 condition, the M-BCI-thresholds were 1.7 dB (SD, 2.2dB; p = 0.002) more favorable than with S-BCI. For the S0N180 configuration, an improvement of 5.8 dB (SD, 2.8 dB; p < 0.001) was seen for the directional mode relative to S-BCI. The APHAB showed statistically significant subjective improvement with the M-BCI on all subscales relative to S-BCI. Speech intelligibility in noise is better with M-BCI than with S-BCI. This was attributed to better high-frequency gain provided by the M-BCI. Improved signal processing strategies may have contributed to subjective preference for the M-BCI.

Hearing Preservation Surgery for Cochlear Implantation—Hearing and Quality of Life After 2 Years

To study the benefits of hearing preservation surgery in cochlear implantation after 2 years. A retrospective cohort study. Performed at a single academic institution between 2008 and 2010 Thirteen patients (1 bilateral): 43% male and 57% female subjects. Mean age at surgery was 51 years (range, 32-72 yr). Average duration of deafness was 25 years (range, 5-62 yr). Hearing preservation cochlear implantation surgery performed with the Med-El FlexEAS electrode. Pure tone thresholds, speech perception in quiet and noise and quality of life (Abbreviated Profile of Hearing Aid Benefit [APHAB] and Glasgow Hearing Aid Benefit [GHABP Scales] up to and including 2 years after surgery. At the first postoperative audiogram, the hearing preservation rate was 100% (complete (42.9%), partial (50%), and minimal (7.1%)). After 24 months, the breakdown was complete (25%), partial (12.5%), minimal (37.5%) and complete loss (12.5%). There was a trend in improvement in all areas of APHAB) with significant improvements in the background noise and reverberation categories as well as the global scores. The GHABP scores showed high levels of use, benefit, and low levels of residual disease. Hearing preservation can be achieved in the short term but deteriorates with time over the medium term at a rate greater than that can be expected with the natural progression of the disease. Patients show benefits in speech outcomes and quality of life regardless of whether hearing preservation was achieved in the medium term.

Temporal Processing and Speech Perception in Noise by Listeners with Auditory Neuropathy

AimThe present study evaluated the relation between speech perception in the presence of background noise and temporal processing ability in listeners with Auditory Neuropathy (AN).MethodThe study included two experiments. In the first experiment, temporal resolution of listeners with normal hearing and those with AN was evaluated using measures of temporal modulation transfer function and frequency modulation detection at modulation rates of 2 and 10 Hz. In the second experiment, speech perception in quiet and noise was evaluated at three signal to noise ratios (SNR) (0, 5, and 10 dB).ResultsResults demonstrated that listeners with AN performed significantly poorer than normal hearing listeners in both amplitude modulation and frequency modulation detection, indicating significant impairment in extracting envelope as well as fine structure cues from the signal. Furthermore, there was significant correlation seen between measures of temporal resolution and speech perception in noise.ConclusionResults suggested that an impaired ability to efficiently process envelope and fine structure cues of the speech signal may be the cause of the extreme difficulties faced during speech perception in noise by listeners with AN.

The Effectiveness of Bilateral Cochlear Implants for Severe-to-Profound Deafness in Adults

Assessment of the clinical effectiveness of bilateral cochlear implantation compared with unilateral cochlear implantation or bimodal stimulation, in adults with severe-to-profound hearing loss. In 2007, the National Institute for Health and Clinical Excellence (NICE) in the U.K. conducted a systematic review on cochlear implantation. This study forms an update of the adult part of the NICE review. The electronic databases MEDLINE and Embase were searched for English language studies published between October 2006 and March 2011. Studies were included that compared bilateral cochlear implantation with unilateral cochlear implantation and/or with bimodal stimulation, in adults with severe-to-profound sensorineural hearing loss. Speech perception in quiet and in noise, sound localization and lateralization, speech production, health-related quality of life, and functional outcomes were analyzed. Data extraction forms were used to describe study characteristics and the level of evidence. The effect size was calculated to compare different outcome measures. Pooling of data was not possible because of the heterogeneity of the studies. As in the NICE review, the level of evidence of the included studies was low, although some of the additional studies showed less risk of bias. All studies showed a significant bilateral benefit in localization over unilateral cochlear implantation. Bilateral cochlear implants were beneficial for speech perception in noise under certain conditions and several self-reported measures. Most speech perception in quiet outcomes did not show a bilateral benefit. The current review provides additional evidence in favor of bilateral cochlear implantation, even in complex listening situations.

Cochlear implant optimized noise reduction

Noise-reduction methods have provided significant improvements in speech perception for cochlear implant recipients, where only quality improvements have been found in hearing aid recipients. Recent psychoacoustic studies have suggested changes to noise-reduction techniques specifically for cochlear implants, due to differences between hearing aid recipient and cochlear implant recipient hearing. An optimized noise-reduction method was developed with significantly increased temporal smoothing of the signal-to-noise ratio estimate and a more aggressive gain function compared to current noise-reduction methods. This optimized noise-reduction algorithm was tested with 12 cochlear implant recipients over four test sessions. Speech perception was assessed through speech in noise tests with three noise types; speech-weighted noise, 20-talker babble and 4-talker babble. A significant speech perception improvement using optimized noise reduction over standard processing was found in babble noise and speech-weighted noise and over a current noise-reduction method in speech-weighted noise. Speech perception in quiet was not degraded. Listening quality testing for noise annoyance and overall preference found significant improvements over the standard processing and over a current noise-reduction method in speech-weighted and babble noise types. This optimized method has shown significant speech perception and quality improvements compared to the standard processing and a current noise-reduction method.

Functional benefits of sequential bilateral cochlear implantation in children with long inter-stage interval between two implants

ObjectivesOlder children are increasingly deriving binaural benefits from sequential bilateral cochlear implantation, and this procedure should be considered by experienced cochlear implant centers. This study aimed to identify the influence of a long inter-stage interval between two implants in older children. Speech perception and everyday listening performance were investigated and analyzed according to the length of the inter-stage interval. Study design and settingsForty-two children who received sequential bilateral cochlear implantation participated in this study. Their average ages at the first and second implantation were 4.2 and 9.7years, respectively. All subjects acquired excellent speech performance from their first implant, and the mean inter-stage interval was 5.5years. Speech perception in quiet was assessed by formal speech measures, and postoperative performance using the second implant only was compared with the preoperative performance. Speech perception in noise test was administered using three noise directions with noise (+10dB signal-to-noise ratio) from front and 90° to each side, and the change in performance using the first implant only and both implants were analyzed across the three noise directions. Subjects were divided into three groups according to their inter-stage interval (group I, 3–4.9years; group II, 5–6.9years; and group III, 7–9.9years), and the test results were compared between the groups. Functional hearing benefits in daily life were measured by a questionnaire before and after bilateral cochlear implantation. ResultsThe speech perception abilities in quiet using the second implant only improved quickly and were similar to those using the first implant only within 1year after the second implantation. The scores for the monosyllabic word test (phoneme: p=0.052; word: p=0.125) and common phrases sentence test (p=0.062) 6month after the second implantation, and the Categories of Auditory Performance score (p=1.000) 1year after the second implantation using the second implant only did not differ significantly from those using the first implant only. Speech perception was significantly better using both implants than using the first implant in all three noise conditions (speech and noise in front: p=0.004; speech in front and noise to the first implant: p=0.003; speech in front and noise to the second implant: p<0.001), and the effect of noise direction was negligibly small. No salient influence of inter-stage interval was observed in both quiet and noise tests. The second and third groups with longer inter-stage intervals (>5years) achieved performance close to the level of the first group with a shorter interval. These subjects obtained significantly better functional hearing benefits in the everyday environment with bilateral implants compared with the first implant (p=0.018). ConclusionThe subjects in this study showed rapid postoperative progression within 6months after the second implantation, and more listening benefits in noise and daily life with bilateral implants. This group of older children, who were good performers with the first implant, developed auditory perceptual competence in the second ear and achieved functional binaural benefits with their two implants. Sequential bilateral cochlear implantation should be recommended to this group of older children despite a long inter-stage interval between two implants.

Speech perception and localisation with SCORE bimodal: a loudness normalisation strategy for combined cochlear implant and hearing aid stimulation.

A significant fraction of newly implanted cochlear implant recipients use a hearing aid in their non-implanted ear. SCORE bimodal is a sound processing strategy developed for this configuration, aimed at normalising loudness perception and improving binaural loudness balance. Speech perception performance in quiet and noise and sound localisation ability of six bimodal listeners were measured with and without application of SCORE. Speech perception in quiet was measured either with only acoustic, only electric, or bimodal stimulation, at soft and normal conversational levels. For speech in quiet there was a significant improvement with application of SCORE. Speech perception in noise was measured for either steady-state noise, fluctuating noise, or a competing talker, at conversational levels with bimodal stimulation. For speech in noise there was no significant effect of application of SCORE. Modelling of interaural loudness differences in a long-term-average-speech-spectrum-weighted click train indicated that left-right discrimination of sound sources can improve with application of SCORE. As SCORE was found to leave speech perception unaffected or to improve it, it seems suitable for implementation in clinical devices.

Speech Identification with Temporal and Spectral Modification in Subjects with Auditory Neuropathy

Background. The aim of this study was to investigate the individual effects of envelope enhancement and high-pass filtering (500 Hz) on word identification scores in quiet for individuals with Auditory Neuropathy. Method. Twelve individuals with Auditory Neuropathy (six males and six females) with ages ranging from 12 to 40 years participated in the study. Word identification was assessed using bi-syllabic words in each of three speech processing conditions: unprocessed, envelope-enhanced, and high-pass filtered. All signal processing was carried out using MATLAB-7. Results. Word identification scores showed a mean improvement of 18% with envelope enhanced versus unprocessed speech. No significant improvement was observed with high-pass filtered versus unprocessed speech. Conclusion. These results suggest that the compression/expansion signal processing strategy enhances speech identification scores—at least for mild and moderately impaired individuals with AN. In contrast, simple high-pass filtering (i.e., eliminating the low-frequency content of the signal) does not improve speech perception in quiet for individuals with Auditory Neuropathy.

Musical background not associated with self-perceived hearing performance or speech perception in postlingual cochlear-implant users

In normal-hearing listeners, musical background has been observed to change the sound representation in the auditory system and produce enhanced performance in some speech perception tests. Based on these observations, it has been hypothesized that musical background can influence sound and speech perception, and as an extension also the quality of life, by cochlear-implant users. To test this hypothesis, this study explored musical background [using the Dutch Musical Background Questionnaire (DMBQ)], and self-perceived sound and speech perception and quality of life [using the Nijmegen Cochlear Implant Questionnaire (NCIQ) and the Speech Spatial and Qualities of Hearing Scale (SSQ)] in 98 postlingually deafened adult cochlear-implant recipients. In addition to self-perceived measures, speech perception scores (percentage of phonemes recognized in words presented in quiet) were obtained from patient records. The self-perceived hearing performance was associated with the objective speech perception. Forty-one respondents (44% of 94 respondents) indicated some form of formal musical training. Fifteen respondents (18% of 83 respondents) judged themselves as having musical training, experience, and knowledge. No association was observed between musical background (quantified by DMBQ), and self-perceived hearing-related performance or quality of life (quantified by NCIQ and SSQ), or speech perception in quiet.