An investigation on the maturation of hearing abilities in children

A number of pure-tone tests were presented to 8 groups of children of different ages who had no ear, nose, and throat pathology and a normal I.Q., in order to investigate the degree of maturation of their hearing abilities. The Luescher test (identification of difference limen or intensity) showed a significant relationship between increasing age and precise identification of gradually decreasing levels of intensity. Performance on this test was shown to be very reliable in children, and may be used as an indication of the degree of physiological maturation of hearing abilities.     

Effects of stimulus level on the speech perception abilities of children using cochlear implants or digital hearing aids

OBJECTIVE: The present investigation was designed to provide information to facilitate the decision of whether a child should continue using digital signal processing (DSP) hearing aids with wide dynamic range compression (WDRC) or be recommended for a cochlear implant, based on the unaided pure-tone average (PTA at 500, 1000, and 2000 Hz). DESIGN: Fifty-two children (ages 5 to 15 yr) with unaided PTAs in the moderately severe to profound range, wearing (DSP) hearing aids with (WDRC) or a Nucleus 24, Clarion 1.2, or CII cochlear implant system, participated: 26 with unaided PTAs from 60 to 98 dB HL using DSP hearing aids and 26 with pre-implant unaided PTAs from 93 to 120 dB HL, using cochlear implants. An open-set speech perception test, the Lexical Neighborhood Test (LNT; ), was administered at intensity levels representative of raised (70 dB SPL) and soft (50 dB SPL) speech at two different times approximately 1 mo apart. Minimum audibility of soft sounds was determined for the children with implants and with DSP hearing aids using warble-tone thresholds at octave intervals between 250 and 4000 Hz. RESULT: Regression analyses and significance testing were used to determine the unaided PTA values at which the performance of the DSP Hearing Aid group (DSP HA group) and Cochlear Implant group on the LNT test were statistically different at the 0.05 significance level. For the 70 dB SPL presentation level, the statistically different PTAs were 113 and 97 dB HL at Time 1 and Time 2, respectively, and 96 and 88 dB HL at 50 dB SPL for Time 1 and Time 2, respectively. CONCLUSIONS: The Unaided PTA at which children in the cochlear implant group would be expected to score significantly better than the children in the DSP HA group was lowest (96 and 88 dB HL) for the lower signal level (50 dB SPL). Assuming that LNT scores at 50 dB SPL are representative of long-term hearing of soft incidental speech that is essential for language learning and fluent communication, the children with PTA values greater than the range from 88 to 96 dB HL would be expected to have significantly better LNT scores with a cochlear implant. These results should be further examined with research efforts focusing on early intervention with optimally fitted DSP hearing aids and cochlear implants.     

Phonological abilities of hearing-impaired Cantonese-speaking children with cochlear implants or hearing AIDS.

PURPOSE: This article examined the phonological skills of 2 groups of Cantonese-speaking children with prelingual, profound bilateral hearing loss. The phonological abilities of 7 children fitted with hearing aids were compared with the abilities of 7 children who wore cochlear implants. METHOD: Participants in each group ranged in age from 5;1 to 6;4 years. The participants were asked to name 57 pictures and retell 2 stories. Phonological abilities were described in terms of the participants' phonological units and the phonological processes used. The participants' perception of single words was assessed using a Cantonese phonology test that includes tonal, segmental, and semantic distracters. RESULTS: All except 1 participant had incomplete phonetic repertories. All participants showed complete vowel and tone inventories. The study group used both developmental rules and nondevelopmental phonological rules. For perception of single words, participants chose the target word most often. The cochlear implant users had a significantly higher percentage correct score for consonant production than hearing aid users. CONCLUSIONS: The prediction that Cantonese children wearing cochlear implants would have better phonological skills than children having hearing aids with a similar degree of hearing loss was confirmed. Cochlear implant usage appeared to promote consonant feature production development to a greater degree than did the use of a hearing aid.     

Effects of cadmium on the hearing system.

The functional resemblance between kidney proximal tubular and inner ear epithelial cells which has often been pointed out in the literature led us to hypothesize that nephrotoxic agents that cause renal tubular injury might also impair the function of inner ear cells. As one of the most toxic environmental nephrotoxic agents is cadmium, we aimed to study its effects on hearing experimentally in rats. In this study, increased blood and renal cortical cadmium levels were associated with high cadmium accumulation in ear ossicles and labyrinth in rats exposed to cadmium. The changes in auditory brainstem response (ABR) and otoacoustic emission in 2-month-old male rats exposed to drinking water containing 5 and 15 ppm CdCl2 for 30 days showed that cadmium-induced nephrotoxicity was associated with signs of defective hearing at a concentration of 15 ppm CdCl2 but that 5 ppm CdCl2 caused hearing loss without affecting kidney function. The mean latency of ABR wave 1, which indicates the function of the cochlea, was 1.335 +/- 0.31 ms in the control group and 1.641 +/- 0.052 and 1.74 +/- 0.88 ms in the rats subjected to 5 and 15 ppm CdCl2, respectively (p < 0.001). In the cadmium-treated groups short interpeak wave I-III latencies (p < 0.01) indicated cochlear dysfunction and this was also supported by the distortion product otoacoustic emission results (p < 0.001). Non-significant changes in wave III and V latencies were accepted as evidence of unaltered function of the other parts of the auditory system. These results suggest that hair cells are more sensitive to cadmium than kidney tubule cells and that the cochlear component of hearing is more vulnerable to cadmium toxicity than other parts of the auditory system.     

The hearing of the patients treated with hemodialysis: a long term follow-up study.

Sensorineural hearing loss is frequently found in the patients under the treatment with hemodialysis, but the responsible etiological factor(s) still remains controversial. The purpose of the present study was to determine by a long term follow-up study whether hemodialysis per se or other factors induce sensorineural hearing loss. Thirty-seven patients with the observation periods of 4 years or longer were selected for the analysis. Hearing tests were performed soon after the initiation of hemodialysis and every 3 to 12 months thereafter. Significant hearing loss was found in 16 cases (31 ears) at the first test. Although 3 cases (5 ears) of the initially normal group and one case (2 ears) of the group with already existing hearing loss exhibited significant hearing loss, the change in the hearing level was quite minimal in remaining 67 ears during the observation period. Although the cochlea in patients under the treatment with hemodialysis is susceptible to various insults, we conclude that hemodialysis per se does no harm to the cochlea and the hearing can be maintained at the pre-hemodialysis level in the majority of the cases.     

Discriminating and responsiveness abilities of two hearing handicap scales

Several scales exist for screening handicap and assessing rehabilitation in elderly individuals with hearing loss. There are few comparative studies, however, to suggest which scales perform best. Using receiver-operating curves and responsiveness indices, we examined the relative discriminating ability and sensitivity to detect change of four scales: a long and short version of the Hearing Handicap Inventory in the Elderly (HHIE-L, HHIE-S), and a long and short version of the Revised Quantified Denver Scale of Communication Function (RQDS-L, RQDS-S). All scales were administered to 137 elderly veterans with hearing loss and 101 elderly veterans without hearing loss. Follow-up testing to determine relative ability to detect change was assessed in hearing impaired individuals only after they had used a hearing aid for 4 months. Discriminative accuracy for correctly identifying individuals with hearing loss were: HHIE-L 78%, HHIE-S 79%, RQDS-L 73%, and RQDS-S 74%. Overall differences between the HHIE-S and the RQDS-S were not statistically significant (p = 0.06). True positive results were greater with the HHIE-S compared to the RQDS-S (p = 0.03). Responsiveness indices were: HHIE-L 1.78, HHIE-S 1.86, RQDS-L 1.04, and RQDS-S 1.07. Differences between the HHIE-S and the RQDS-S were statistically significant (p less than 0.05). We conclude short versions of the HHIE and RQDS are as accurate and sensitive for detecting change as long versions, and the HHIE-S is a superior versatile instrument for screening and assessing rehabilitation in elderly individuals with hearing impairment.     

Effects of CIC hearing aids on auditory localization by listeners with normal hearing.

An experiment was conducted to determine the effects of completely-in-the-canal (CIC) hearing aids on auditory localization performance. Six normal-hearing listeners localized a 750-ms broadband noise from loudspeakers ranging in azimuth from -180 degrees to +180 degrees and in elevation from -75 degrees to +90 degrees. Independent variables included the presence or absence of the hearing aid and the elevation of the source. Dependent measures included azimuth error, elevation error, and the percentage of trials resulting in a front-back confusion. The findings indicate a statistically significant decrement in localization acuity, both in azimuth and elevation, occasioned by the wearing of CIC hearing aids. However, the magnitude of this decrement was small compared to those typically caused by other ear-canal occlusions, such as earplugs, and would probably not engender mislocalization of real-world sounds.     

Effects of acknowledging a hearing loss on social interactions

An important part of the counseling process is to offer guidance to people with hearing impairments on accepting their disability and adjusting to the negative attitudes held by some communications partners. The purpose of this study was to determine subjects' (1) preferences for interacting with individuals with a hearing impairment who acknowledged their hearing loss, and (2) perceptions of personality, employability, intelligence, and adjustment related to acknowledgment of hearing loss. Two male students with hearing impairments were videotaped under two experimental conditions. During one condition students acknowledged their hearing losses, spoke about adjustment, concerns, etc., while during the other condition they did not acknowledge their hearing loss. Results indicated that subjects preferred speakers when they discussed their hearing loss. Speakers who acknowledged their hearing loss also received more favorable ratings on personality, employability, and adjustment. Clinical implications for aural rehabilitation programs are discussed.     

An assessment of cognitive abilities in hearing and hearing-impaired preschool children

There have been many investigations of cognitive development in older hearing-impaired children, but few with preschool hearing-impaired children. The performance of 40 hearing and 40 hearing-impaired children of preschool age (2 1/2 to 5 1/2 years) was compared on five nonverbal cognitive tasks and three subtests from the Perceptual Performance subscale of the McCarthy Scales of Children's Abilities (1972). For this set of tasks there was a significant effect of age consistent with a developmental change. A one-way MANCOVA on all dependent measures with age as the covariate revealed no significant differences between the hearing-impaired and hearing children. The results suggest that despite a deficiency in language abilities, the cognitive development of young hearing-impaired children is comparable to that of hearing children of the same age.     

Relations between psychophysical measures of spatial hearing and self-reported spatial-hearing abilities

Objective: The aim of the present study was to investigate how well the virtual psychophysical measures of spatial hearing from the preliminary auditory profile predict self-reported spatial-hearing abilities. Design: Virtual spatial-hearings tests (conducted unaided, via headphones) and a questionnaire were administered in five centres in Germany, the Netherlands, Sweden, and the UK. Correlations and stepwise linear regression models were calculated among a group of hearing-impaired listeners. Study sample: Thirty normal-hearing listeners aged 19–39 years, and 72 hearing-impaired listeners aged 22–91 years with a broad range of hearing losses, including asymmetrical and mixed hearing losses. Results: Several significant correlations (between 0.24 and 0.54) were found between results of virtual psychophysical spatial-hearing tests and self-reported localization abilities. Stepwise linear regression analyses showed that the minimum audible angle (MAA) test was a significant predictor for self-reported localization abilities (5% extra explained variance), and the spatial speech reception threshold (SRT) benefit test for self-reported listening to speech in spatial situations (6% extra explained variance). Conclusions: The MAA test and spatial SRT benefit test are indicative measures of everyday binaural functioning. The binaural SRT benefit test was not found to predict self-reported spatial-hearing abilities.     

5-磷酸二酯酶抑制剂对噪声性聋影响的实验研究

目的探讨5-磷酸二酯酶(PDE5)抑制剂对豚鼠噪声性聋的影响。方法豚鼠随机数字表法分为对照组、噪声暴露组和西地那非给药组,每组15只。西地那非组及噪声组豚鼠在白噪声暴露1周后分别腹腔注射西地那非10mg/(kg.d)及生理盐水4 ml/(kg.d),连续给药4周。分别测试噪声暴露前1天、噪声暴露后1、2及4周听性脑干反应(ABR)阈值及80dB HL下ABRⅠ波潜伏期,并通过扫描电镜观察噪声暴露后4周豚鼠耳蜗毛细胞的形态变化。结果与噪声暴露前相比,西地那非组ABR阈值及Ⅰ波潜伏期均小于噪声组,差异具有统计学意义(P值均<0.01)。扫描电镜显示,噪声组豚鼠耳蜗内、外毛细胞均出现听毛紊乱、融合及缺失;而西地那非组耳蜗病变较轻,听毛仅有轻微倒伏、融合现象。结论西地那非能够减轻噪声对豚鼠耳蜗毛细胞的损害,降低噪声性听觉损伤引起的ABR阈值升高,缩短其引起的Ⅰ波潜伏期延长。     

Spatial hearing with a single cochlear implant in late-implanted adults

We assessed sound localisation abilities of late-implanted adults fitted with a single cochlear implant (CI) and examined whether these abilities are affected by the duration of implant use. Ten prelingually and four postlingually deafened adults who received a unilateral CI were tested in a sound-source identification task. Above chance performance was observed in those prelingual CI recipients who had worn their implant for longer time (9 years on average), revealing some monaural sound localisation abilities in this population but only after extensive CI use. On the contrary, the four postlingual recipients performed equal or better with respect to the best prelingual participants despite shorter experience with the monaural implant (11 months on average). Our findings reveal that some sound localisation ability can emerge in prelingually deafened adults fitted with a single implant, at least in a controlled laboratory setting. This ability, however, appears to emerge only after several years of CI use. Furthermore, the results of four postlingually deafened adults suggest that early experience with auditory cues may result in more rapid acquisition of spatial hearing with a single CI.     

Comparative effects of unilateral and bilateral bone conduction hearing devices on functional hearing and sound localization abilities in patients with bilateral microtia-atresia

Abstract

Background: Various amplification options are available for patients with congenital bilateral conductive hearing loss. Unilateral bone conduction hearing device (BCHD) is widely used for these patients, whereas benefits of bilateral BCHDs in certain subgroups of patients require further exploration.

Objectives: To evaluate functional and directional hearing in patients with unilateral Bonebridge (MEDEL) and contralateral ADHEAR (MEDEL) devices.

Materials and methods: This study included 32 patients (20 males, 12 females), of mean age 11.8?years (range 7–27?years). Hearing thresholds, speech perception and sound localization were tested three months after activation of the Bonebridge under three conditions: unaided, unilateral BHCD (Bonebridge) and bilateral BHCDs (Bonebridge plus contralateral ADHEAR). Patient acceptance of these devices in daily life was evaluated by questionnaire.

Results: Compared with unaided, the mean hearing thresholds (0.5, 1, 2, and 4?kHz) and speech perception with unilateral BCHD and bilateral BCHDs were improved significantly (p?<?.05 each). Markers of directional hearing ability, including percentages of accurate responses, bias angles and RMS errors, were significantly better with bilateral BCHDs than unilateral BHCD (p?<?.05 each). Questionnaire revealed high patient satisfaction with both unilateral and bilateral devices.

Conclusions: Functional hearing and sound localization abilities were better with bilateral BCHDs than unilateral BCHD.     

Effects of interferon-alpha2b on hearing

The aim of the present study was to investigate the effects of interferon-alpha2b treatment on hearing in patients with chronic active hepatitis B. Twenty-six patients with chronic active hepatitis B were enrolled in the study, and pure-tone audiometry was performed to determine hearing thresholds of the patients before and at the end of 6 months of interferon-alpha2b treatment. There was no significant change in hearing thresholds of patients after treatment with interferon-alpha2b (p>0.05). The results of the present study indicate that interferon-alpha2b therapy does not have any negative effect on hearing thresholds of patients with chronic active hepatitis B. There is a need for further studies involving larger numbers of patients to allow conclusions to be drawn regarding the safety of this therapy with respect to hearing.     

Effects of hearing loss on echo thresholds

OBJECTIVE: The purpose of this investigation was to determine the effects of hearing loss on the perception of echoes. DESIGN: Echo thresholds were measured for eight listeners with normal hearing and nine listeners with impaired hearing. Pairs of 4-msec noise bursts were presented to each listener with onset-to-onset delays ranging from 2 to 16 msec. Echo thresholds were obtained at signal presentation levels of 10, 20, 30, 40, and 50 dB SL. RESULTS: Results revealed differences between the psychometric functions of the two subject groups. Psychometric functions of the subjects with impaired hearing indicated higher echo thresholds than for the subjects with normal hearing. In addition, echo thresholds at 10 dB SL were significantly higher than echo thresholds measured at 40 dB SL for both subject groups. CONCLUSION: Listeners with impaired hearing exhibit higher echo thresholds than listeners with normal hearing. The higher echo thresholds for listeners with impaired hearing may account, at least in part, for difficulty on tasks such as localization in everyday listening environments.     

Sudden hearing loss in an adolescent following a single dose of cisplatin

Progressive hearing loss after cisplatin therapy is relatively frequent, specially in older patients, but it is less common in children and in acute form. The case of a 17-year-old patient with an intracranial tumor who suffered sudden deafness after a single course of cisplatin is presented. This patient had a previously documented very good hearing up to 20 kHz. Although it has been suggested that children with irradiated brain tumors may have an increased susceptibility to cisplatin-induced hearing loss, in this case the patient had not been subjected to radiotherapy.     

Audiovisual integration and lipreading abilities of older adults with normal and impaired hearing

OBJECTIVE: The purpose of the current study was to examine how age-related hearing impairment affects lipreading and auditory-visual integration. The working hypothesis for the investigation was that presbycusic hearing loss would increase reliance on visual speech information, resulting in better lipreading and auditory-visual integration in older persons who have hearing impairment, compared with older persons who have normal hearing. DESIGN: This study compared the performance of 53 adults with normal hearing (above age 65) and 24 adults with mild-to-moderate hearing impairment (above age 65) on auditory-only (A), visual-only (V), and auditory-visual (AV) speech perception, using consonants, words, and sentences as stimuli. All testing was conducted in the presence of multi-talker background babble, set individually for each participant and each type of stimulus, to obtain approximately equivalent A performance across the groups. In addition, we compared the two groups of participants on measures of auditory enhancement, visual enhancement, and auditory-visual integration that were derived from the A, V and AV performance scores. RESULTS: In general, the two groups of participants performed similarly on measures of V and AV speech perception. The one exception to this finding was that the participants with hearing impairment performed significantly better than the participants with normal hearing on V identification of words. Measures of visual enhancement, auditory enhancement, and auditory-visual integration did not differ as a function of hearing status. CONCLUSIONS: Overall, the results of the current study suggest that despite increased reliance on visual speech information, older adults who have hearing impairment do not exhibit better V speech perception or auditory-visual integration than age-matched individuals who have normal hearing. These findings indicate that inclusion of V and AV speech perception measures can provide important information for designing maximally effective audiological rehabilitation strategies.     

Effectiveness of a single and a repeated screen for hearing loss in the elderly

The aim of this study was to assess the value of repeated audiometric screens offered to elderly in general practice. In 1991, an audiometric screen was performed on 660 participants, aged 60 years and over, enlisted in one general practice near Rotterdam, the Netherlands. We repeated the audiometric screen 5 years later in 80.2% (405/505) of the eligible participants of the first screen. After the first screen, 24.3% of those who were hearing impaired had discussed this with their general practitioner, 21.5% were referred to a specialist in otolaryngology and 12.1% had been prescribed a hearing aid. The effect of the repeated screen was lower as only 7.3% of the hearing impaired participants received a hearing aid. Efforts to screen on hearing loss will be fruitless and can best be avoided by general practitioners unless strategies are developed to increase the use of hearing aids after a positive screening result.