Audiology : official organ of the International Society of Audiology最新文献

The high incidence of hearing impairment in the Arabic-speaking population in Israel, as well as the use of advanced aural rehabilitation devices, motivated the development of Arabic speech assessment tests for this population. The purpose of this paper is twofold. The first goal is to describe features that are unique to the Arabic language and that need to be considered when developing such speech tests. These include Arabic diglossia (i.e., the sharp dichotomy between Literary and Colloquial Arabic), emphatization, and a simple vowel system. The second goal is to describe a new analytic speech test that assesses the perception of significant phonological contrasts in the Colloquial Arabic variety used in Israel. The perception of voicing, place, and manner of articulation, in both initial and final word positions, was tested at four sensation levels in 10 normally-hearing subjects using a binary forced-choice paradigm. Results show a relationship between percent correct and presentation level that is in keeping with articulation curves obtained with Saudi Arabic and English monosyllabic words. Furthermore, different contrasts yielded different articulation curves: emphatization was the easiest to perceive whereas place of articulation was the most difficult. The results can be explained by the specific acoustical features of Arabic.

Three patients with neurofibromatosis type 2 who had undergone previous cochlear nerve tumour removal were implanted with the Nucleus 21-channel auditory brainstem implant (ABI). The time intervals between tumour removal and implantation were 4, 5, and 7 years, respectively. Total bilateral deafness was confirmed before implantation. One patient was also blind after acute intracranial hypertension. The translabyrinthine approach was used in all cases. The choice of side for implantation depended on pre-operative magnetic resonance imaging study, the facial nerve function, the presence of recurrent and/or other lesions, and the patient's preference. Although the scarring of prior surgical procedure largely changed the anatomical structures in the cerebello-pontine angle, various landmarks could be found to locate the foramen of Luschka, where the ABI electrode was inserted into the lateral recess of the fourth ventricle. During surgery, the electrically evoked auditory brainstem responses were recorded to confirm that the ABI stimulation activated the auditory system; the electromyogram of the 7th and 9th nerves was helpful in finding the landmarks and minimising the triggering of the cranial nerves with ABI stimulation. The number of active electrodes was 21, 7, and 4 in the three patients. All obtained meaningful pitch scaling and useful auditory sensations. One patient, with 21 activated electrodes, has achieved functional open-set speech understanding. The second patient, with 7 activated electrodes, has benefited from environmental sound awareness and improved lipreading. The last, blind, patient, with 4 electrodes activated, achieved only perception of environmental sounds.

This study provides further evidence of an ototoxic interaction between red pheomelanin pigmentation and noise-induced hearing loss. Red, black, and albino guinea pigs were treated with a low, a high, or no dose of chloroquine. The 2f1-f2 distortion product otoacoustic emission (DPOE) measurements were measured before, immediately after, and 1 month after noise exposure to a 1-kHz tone at 105 dB SPL for 72 hours. In red guinea pigs, the DPOE was severely affected by noise trauma when treated even by a low single dose of chloroquine, whereas in both albino and black guinea pigs, the chloroquine effect on the DPOE was temporary and present only when the drug was given in a high single dose. The structure most likely to be responsible for the severe loss of DPOE in chloroquine-treated red animals is the strial melanocyte. The damage may be triggered by an ototoxic noise-induced production of radical oxygen species from pheomelanin, for example, by the Fenton reaction or due to the increased variability of the melanocyte 1 receptor gene as in red-haired individuals.

There is very limited information available about hearing loss in children in Latin America and in Central America in particular. Costa Rica is a peaceful, well-organized country with an excellent health care system and a very good infrastructure of roads, programs, and services. It served as the site for a four-phase study to determine the incidence and prevalence rate for sensorineural hearing loss in children in that region of the world. The four phases involved (1) screening over 12,500 children in the public schools, (2) examining those enrolled at programs for the hearing impaired, (3) searching the community for children not in schools or special programs, and (4) an extensive questionnaire designed to obtain basic demographic data about hearing-impaired children in the country. Included were questions about age of identification, etiology, and hearing aid use. Results of phases 1 and 2 are reported here. Using a 1.368 per 1,000 live birth average (a figure reported for 36 nations), the projected number of hearing-impaired children in Costa Rica should be about 1,068. After concluding the first two phases of the study, it was determined that the actual number of hearing-impaired children in Costa Rica is between 1,174 and 1,274. That is a ratio of between 1.50 and 1.63 hearing impaired per 1,000 live births, well within the ranges reported elsewhere. Since this is the first national study of a Latin American country, that information is significant, suggesting that the general prevalence of hearing loss in that part of the world is the same as in the developed nations of Europe and North America.

The majority of patients with tinnitus experience a lessening of their symptoms during an 18-month period after their first consultation. The exception to this rule is severe incapacitating tinnitus, the sometimes very troublesome symptoms of which show no sign of diminishing with time. The aim of the present study was to investigate risk factors for incapacitating tinnitus, as measured by absence from work related to tinnitus (AWT) of more than 1 month during an 18-month period after the first visit to the tinnitus clinic. Audiometric data and the scores from the Tinnitus Severity Questionnaire and the Nottingham Health Profile at the first visit to the clinic were correlated to AWT by a logistic regression model. By using this risk model, an individual risk score for AWT could be estimated. Depression and physical immobility were strong predictors of AWT, and hearing loss was moderate. Based on these results, we suggest that the aetiology of tinnitus severity could be described as depression-/anxiety-related, somatic, and auditory tinnitus.

Skin-penetrating titanium implants have been used to anchor bone-anchored hearing aids (BAHAs) since 1977. The aim of the present immunohistochemical study was to analyse the distribution of inflammatory cell types in the skin penetration site with a panel of monoclonal antibodies. Many inflammatory cells were present at the tissue-implant interface but decreased gradually in number from the interface. The predominating cell types in the dermis in clinically non-inflamed tissue were T lymphocytes and macrophages, indicating a chronic inflammatory response. In specimens from clinically inflamed tissue, a large number of polymorphonuclear positive cells were present. B lymphocytes and plasma cells were also found, indicating that bacterial infections were superimposed on the chronic inflammatory response. An additional aim was to revise the clinical scoring system based on the present findings and earlier histological results.

In this study, we measured the effects of a digital hearing aid on speech recognition or reception in noise for two noise reduction concepts: active noise reduction by speech-sensitive processing (SSP) and improved directionality by a dual- or so-called twin-microphone system (TMS). This was conducted in a well-controlled clinical field trial in 16 hearing-aid users, using a single-blind crossover design. The hearing aid fitting was controlled by insertion gain measurements and measurements with loudness scaling. This study combined laboratory experiments with three consecutive field trials of 4 weeks each. We used performance measurements (speech recognition tests in background noise), paired comparisons, and self-report measurements (questionnaires). The speech recognition or reception tests were performed before and after each field trial, the paired comparisons were performed in weeks 4 and 12, and the questionnaires were administered after each field trial. For all subjects, results were obtained for three different settings: no noise reduction, SSP alone, and TMS alone. In the last week, we also performed speech recognition or reception tests in background noise with both noise reduction concepts combined. Three types of results have been reported: "objective" results from the critical signal to noise ratios for speech recognition or reception in different background noises for different settings and "subjective" results: paired comparisons and questionnaires. The subjective scores show the same trend as the objective scores. The effects of TMS were clearly positive, especially for the speech reception threshold tests and for the paired comparisons. The effects of SSP were much smaller but showed significant benefits with respect to aversiveness and speech perception or reception in noise for specific acoustical environments. There was no extra benefit from the combined effect of SSP and TMS relative to TMS alone.

External ear resonance was measured in elderly people using a probe-tube microphone system. Resonance frequency, amplitude, and bandwidth as well as ear canal volume were compared across age groups and genders. No significant age group trends were observed in external ear resonant frequency. Also, the amplitude and bandwidth of the resonance peaks across ages were not significantly different. For the gender effect, the mean external ear resonant frequencies are generally higher for females than for males in all age groups, but the differences are not statistically significant. The mean amplitudes of the resonant frequency are larger for men than for women. But the difference is also small. For the ear canal volume, no significant age trend was found. However, the mean ear canal volume was significantly larger for males than for females.

The availability of information about prevalence/incidence of hearing impairment in Latin American countries is very limited. A questionnaire on the subject was mailed to most Latin American and Caribbean countries. The information returned by 12 respondents (Argentina, Chile. Columbia, Costa Rica, Cuba, Grenada, Guatemala, Mexico, Nicaragua, Panama, Puerto Rico, and Uruguay) was analyzed. Data are presented about available epidemiological studies on hearing impairment, national registers on deafness, publications on otitis media, and programs on hearing screening. Presence of training programs and available human resources in the broad field of hearing impairment is also discussed. Estimates of the enrollment of deaf children in schools for the deaf is also shown. This review concludes that hearing impairment is a low priority for national health systems in Latin America. material and human resources are limited, audiology services are scarce, and technology continues to be very costly by regional standards.

Listing the eight most important aspects of epidemiological research relevant to hearing loss, this paper reviews some of the difficulties encountered in trying to do such research in the developing world. Various research formats are discussed. This paper concludes with a review of what has been reported in the world's literature about the incidence and prevalence of sensorineural hearing loss in children. The average finding from 34 nations is 1.368 hearing impaired per 1,000.