Inner ear damage in children due to noise exposure from toy cap pistols and firecrackers: a retrospective review of 53 cases.
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This retrospective study presents the findings of inner ear damage documented in 53 children exposed to impulsive sound emitted by toy weapons and firecrackers. There were 49 boys and four girls aged between four and fourteen years. Thirty-nine children were affected unilaterally while fourteen had bilateral hearing loss (total of 67 ears). Most of the hearing loss (>70%) was sensorineural high frequency hearing loss, while only nine out of the 67 injured ears had sensorineural mid frequency hearing loss. Seven children sustained a traumatic ear drum perforation. Dizziness or tinnitus was reported by twenty children, with pathological ENG findings in four of them. This paper re-emphasizes the possibility of inner ear damage in children from exposure to noisy toys. (+info)
Psychophysical metrics and speech recognition in cochlear implant users.
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Intersubject variability in perception is a prominent characteristic of people with cochlear implants. This study characterized intersubject differences using simple metrics based on psychophysical measures: maximum comfortable loudness levels (C levels) and dynamic ranges (DRs). In a group of 17 subjects, we assessed across-site variation (ASV) and across-site mean (ASM) values of C levels and DRs for bipolar (BP) and monopolar (MP) stimulation, and examined the relation of these metrics to speech recognition across subjects. Significant negative correlations with speech recognition were found for ASVs of C levels for BP stimulation; i.e., subjects with high ASVs of BP C levels had poor speech recognition. Positive correlations with speech recognition were found for ASMs of C levels and ASMs of DRs for both BP and MP stimulation; i.e., subjects with high mean C levels and large mean DRs had better speech recognition. Thus, these psychophysical metrics are effective for diagnosis of individual differences in performance of subjects with cochlear implants. Furthermore, they point to some potentially useful treatment procedures. (+info)
Evaluation of speech perception in noise in cochlear implanted adults.
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AIM: To evaluate the effects of different signal-to-noise ratios on speech recognition obtained by the use of cochlear implant (CI); to compare the speech recognition in noise with different types of multichannel cochlear implants (CIs) and to evaluate the degree of difficulty for speech understanding in noise in daily life situations. STUDY DESIGN: Cohort transversal. MATERIAL AND METHOD: Forty adults with post-lingual hearing loss implanted with Nucleus 22, Nucleus 24, Combi 40, Combi 40+ and Clarion. We evaluated the recognition for CPA sentences in quiet and in S/N +15, +10 and +5 dB. We also applied the Social Hearing Handicap Index (SHHI) questionnaire for self-assessment in daily life. RESULTS AND CONCLUSION: All the implanted adults presented a significant reduction in the scores for sentences recognition as the S/N decreased. The medians' curve for sentence recognition reached 50% in the signal-to-noise ratio of +10 dB. There was no statistically significant difference in sentences' recognition scores and difficulty scores obtained with the SHHI, for all types of implants. The difficulties of implanted adults were rare in quiet and occasional in noisy situations according to SHHI questionnaire. (+info)
Speech signals used to evaluate functional status of the auditory system.
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This review presents a brief history of the evolution of speech audiometry from the 1800s to present day. The two-component aspect of hearing loss (audibility and distortion), which was formalized into a framework in past literature, is presented in the context of speech recognition. The differences between speech recognition in quiet and in background noise are discussed as they relate to listeners with normal hearing and listeners with hearing loss. A discussion of the use of sentence materials versus word materials for clinical use is included as is a discussion of the effects of presentation level on recognition performance in quiet and noise. Finally, the effects of age and hearing loss on speech recognition are considered. (+info)
Use of 35 words for evaluation of hearing loss in signal-to-babble ratio: A clinic protocol.
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Data from earlier studies that presented 70 words at 24 to 0 dB signal-to-babble (S/B) ratios indicated that most young listeners with normal hearing required 0 to 6 dB S/B ratios to attain 50% correct word recognition. Older listeners with hearing loss often required a >12 dB S/B ratio to attain 50% correct word recognition. In our study, we converted the Words in Noise test from one 70-word list into two 35-word lists for quicker administration by clinicians. Using baseline data from previous studies, we used two strategies to randomize the 35-word lists: based on recognition performance at each S/B ratio and based on recognition performance only. With the first randomization strategy, the 50% correct word-recognition points on the two lists differed by 0.5 dB for 72 listeners with hearing loss. With the second randomization strategy, 48 listeners with hearing loss performed identically on the two lists. (+info)
Effect of masker type and age on speech intelligibility and spatial release from masking in children and adults.
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Speech recognition in noisy environments improves when the speech signal is spatially separated from the interfering sound. This effect, known as spatial release from masking (SRM), was recently shown in young children. The present study compared SRM in children of ages 5-7 with adults for interferers introducing energetic, informational, and/or linguistic components. Three types of interferers were used: speech, reversed speech, and modulated white noise. Two female voices with different long-term spectra were also used. Speech reception thresholds (SRTs) were compared for: Quiet (target 0 degrees front, no interferer), Front (target and interferer both 0 degrees front), and Right (interferer 90 degrees right, target 0 degrees front). Children had higher SRTs and greater masking than adults. When spatial cues were not available, adults, but not children, were able to use differences in interferer type to separate the target from the interferer. Both children and adults showed SRM. Children, unlike adults, demonstrated large amounts of SRM for a time-reversed speech interferer. In conclusion, masking and SRM vary with the type of interfering sound, and this variation interacts with age; SRM may not depend on the spectral peculiarities of a particular type of voice when the target speech and interfering speech are different sex talkers. (+info)
Simultaneous bilateral cochlear implantation in adults: a multicenter clinical study.
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OBJECTIVE: To determine the efficacy of "simultaneous" bilateral cochlear implantation (both implants placed during a single surgical procedure) by comparing bilateral and unilateral implant use in a large number of adult subjects tested at multiple sites. DESIGN: Prospective study of 37 adults with postlinguistic onset of bilateral, severe to profound sensorineural hearing loss. Performance with the bilateral cochlear implants, using the same speech processor type and speech processing strategy, was compared with performance using the left implant alone and the right implant alone. Speech understanding in quiet (CNCs and HINT sentences) and in noise (BKB-SIN Test) were evaluated at several postactivation time intervals, with speech presented at 0 degrees azimuth, and noise at either 0 degrees , 90 degrees right, or 90 degrees left in the horizontal plane. APHAB questionnaire data were collected after each subject underwent a 3-wk "bilateral deprivation" period, during which they wore only the speech processor that produced the best score during unilateral testing, and also after a period of listening again with the bilateral implants. RESULTS: By 6-mo postactivation, a significant advantage for speech understanding in quiet was found in the bilateral listening mode compared with either unilateral listening modes. For speech understanding in noise, the largest and most robust bilateral benefit was when the subject was able to take advantage of the head shadow effect; i.e., results were significantly better for bilateral listening compared with the unilateral condition when the ear opposite to the side of the noise was added to create the bilateral condition. This bilateral benefit was seen on at least one of the two unilateral ear comparisons for nearly all (32/34) subjects. Bilateral benefit was also found for a few subjects in spatial configurations that evaluated binaural redundancy and binaural squelch effects. A subgroup of subjects who had asymmetrical unilateral implant performances were, overall, similar in performance to subjects with symmetrical hearing. The questionnaire data indicated that bilateral users perceive their own performance to be better with bilateral cochlear implants than when using a single device. CONCLUSIONS: Findings with a large patient group are in agreement with previous reports on smaller groups, showing that, overall, bilateral implantation offers the majority of patients advantages when listening in simulated adverse conditions. (+info)
Effects of temporal fine structure on the lateralization of speech and on speech understanding in noise.
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This study evaluated the role of temporal fine structure in the lateralization and understanding of speech in six normal-hearing listeners. Interaural time differences (ITDs) were introduced to invoke lateralization. Speech reception thresholds (SRTs) were evaluated in backgrounds of two-talker babble and speech-shaped noise. Two-syllable words with ITDs of 0 and 700 micros were used as targets. A vocoder technique, which systematically randomized fine structure, was used to evaluate the effects of fine structure on these tasks. Randomization of temporal fine structure was found to significantly reduce the ability of normal-hearing listeners to lateralize words, although for many listeners, good lateralization performance was achieved with as much as 80% fine-structure randomization. Most listeners demonstrated some rudimentary ability to lateralize with 100% fine-structure randomization. When ITDs were 0 micros, randomization of fine structure had a much greater effect on SRT in two-talker babble than in speech-shaped noise. Binaural advantages were also observed. In steady noise, the difference in SRT between words with 0- vs 700-micros ITDs was, on average, 6 dB with no fine-structure randomization and 2 dB with 100% fine-structure randomization. In two-talker babble this difference was 1.9 dB and, for most listeners, showed little effect of the degree of fine-structure randomization. These results suggest that (1) improved delivery of temporal fine structure would improve speech understanding in noise for implant recipients, (2) bilateral implant recipients might benefit from temporal envelope ITDs, and (3) improved delivery of temporal information could improve binaural benefits. (+info)