Hearing, use of hearing protection, and attitudes towards noise among young American adults.

The purpose of the present study was to investigate possible associations between college students' attitudes, risk-taking behaviour related to noisy activities, and hearing problems such as threshold shifts or self-experienced hearing symptoms. The sample included 258 students aged between 17 and 21 enrolled at the University of Pennsylvania, USA. A questionnaire measuring attitudes towards noise, use of hearing protection, and self-reported hearing symptoms was distributed among the students. After completing the questionnaire a hearing screening, including pure-tone audiometry and tympanometry, was conducted. The result revealed that 26% had thresholds poorer than the screening level of 20 dBHL. Attitudes were significantly related to self-experienced hearing symptoms, but not to threshold shifts. Attitudes and noise sensitivity was, significantly related to use of hearing protection. Hearing protection use was found in activities such as using firearms, mowing lawns, and when using noisy tools but was less reported for concerts and discotheques. It can be concluded that the young adults in this study expose themselves to hearing risks, since the use of hearing protection is in general very low.

Reported hearing protection use in young adults from Sweden and the USA: effects of attitude and gender.

The present study investigates differences between a Swedish and an American sample of young students regarding attitudes towards noise and the use of hearing protection at concerts. The study population was comprised of 179 participants from Sweden and 203 participants from the United States, who ranged in age from 17 to 21 years. Questionnaires were used to gather information on hearing symptoms and attitudes towards noise (Youth Attitude to Noise Scale). Multivariate analysis of variance revealed that attitudes towards noise differed significantly due to gender and country. Men had slightly more positive attitude towards noise than women, and men from the USA had more positive attitudes than men from Sweden. Least positive were the women from Sweden (except regarding attitudes towards the ability to concentrate in noisy environments). Multivariate logistic regression analysis was used to examine the influence of attitudes towards noise and country on young people's use of hearing protection at concerts. The results indicated that attitudes and country explained 50% of the variance in use of hearing protection.

Prospects for circular dichroism detection of nonracemic extraterrestrial organic molecules.

The use of circular dichroism is examined as a probe for the detection of nonracemic analytes on spacecraft explorations such as a planned mission to Titan. Advances in both instrument design and chemistry will be required to make such a method practicable. The focus of this paper is on chemical agents able to amplify the circular dichroism signal, which would simplify instrument problems and increase sensitivity. A classic phenomenon known as the Pfeiffer effect provides a conceptual strategy to achieve the necessary aims for chirality detection. Recent examples of Pfeiffer-related phenomena are discussed.

Estimated prevalence of noise-induced hearing threshold shifts among children 6 to 19 years of age: the Third National Health and Nutrition Examination Survey, 1988-1994, United States.

OBJECTIVE: This analysis estimates the first nationally representative prevalence of noise-induced hearing threshold shifts (NITS) among US children. Historically, NITS has not been considered a common cause of childhood hearing problems. Among children, NITS can be a progressive problem with continued exposure to excessive noise, which can lead to high-frequency sound discrimination difficulties (eg, speech consonants and whistles). METHODS: The Third National Health and Nutrition Examination Survey (NHANES III) was conducted from 1988 to 1994. NHANES III is a national population-based cross-sectional survey with a household interview, audiometric testing at 0.5 to 8 kHz, and compliance testing. A total of 5249 children aged 6 to 19 years completed audiometry and compliance testing for both ears in NHANES III. The criteria used to assess NITS included audiometry indicating a noise notch in at least 1 ear. RESULTS: Of US children 6 to 19 years old, 12.5% (approximately 5.2 million) are estimated to have NITS in 1 or both ears. In the majority of the children meeting NITS criteria, only 1 ear and only 1 frequency are affected. In this analysis, all children identified with NITS passed compliance testing, which essentially rules out middle ear disorders such as conductive hearing loss. The prevalence estimate of NITS differed by sociodemographics, including age and sex. CONCLUSIONS: These findings suggest that children are being exposed to excessive amounts of hazardous levels of noise, and children's hearing is vulnerable to these exposures. These data support the need for research on appropriate hearing conservation methods and for NITS screening programs among school-aged children. Public health interventions such as education, training, audiometric testing, exposure assessment, hearing protection, and noise control when feasible are all components of occupational hearing conservation that could be adapted to children's needs with children-specific research.

An association between dentate status and hearing acuity.

Hearing improvement following dental treatment has been reported in case studies, yet few objective studies of this phenomenon have been conducted. To determine if a relationship exists between dentate status and hearing acuity, we conducted a retrospective study of elderly subjects enrolled in a health promotion clinical trial. Air-conduction pure tone average thresholds (PTA) administered to left and right ears at 500 Hz, 1000 Hz, 2000 Hz, 3000 Hz, 4000 Hz, and 6000 Hz were used to create six hearing outcome variables, and were compared between groups of subjects who either had 25 or more teeth (n = 182) or were edentulous (n = 43). Mean PTA thresholds were significantly greater (p < 0.05) in edentulous subjects for each hearing outcome variable, and differences between unadjusted group means ranged from 4.9 dB to 8.6 dB. Mean PTA thresholds adjusted for clinical factors known to affect hearing also indicated worse hearing acuity in the edentulous group. These pilot findings suggest an association between dentate status and hearing acuity.

Somatosensory phenomena after multichannel cochlear implantation in prelingually deaf adults.

OBJECTIVES: Central auditory system development in thought to be dependent on normal auditory nerve excitation. Central auditory disorganization may differ between prelingual and postlingual deafness. One possible clinical manifestation of such central auditory disorganization is somatosensory perception with cochlear implant stimulation. The purpose of this study was to investigate the incidence and characteristics of somatosensory phenomena in prelingually and postlingually deafened adult cochlear implant subjects. STUDY DESIGN: The study design was a retrospective analysis. SETTING: The study was performed at an academic tertiary referral center. PATIENTS: This study included 32 adult multichannel cochlear implant recipients. MAIN OUTCOME MEASURES: Subjective patient reporting of sensory perception after cochlear implant stimulation was reviewed. RESULTS: All 10 prelingually deaf subjects noted somatosensory phenomena distant from the implanted ear (e.g., chest, abdomen) on implant stimulation. These sensations resolved gradually for all patients. No subject deafened after the age of 2 years reported somatosensory perceptions. CONCLUSIONS: Somatosensory phenomena experienced by prelingually deafened adults suggest that disorganization of central auditory system pathways is more severe in these individuals. Earlier auditory deprivation appears to produce greater central auditory alterations, and perceptible crossover between somatosensory and auditory signals may be the end result.

Screening for hearing loss in juvenile detention centers.

Results of hearing screenings for 226 incarcerated adolescents are presented. Screenings consisted of visual otoscopy check, pure-tone screening, and tympanometry. Failures were defined as excessive cerumen impeding a clear view of the tympanum, failure to respond at 25 dB HL for 1000 through 6000 Hz, or a Jerger Type B or C tympanogram. An overall failure rate of 35.5 percent was found, with 9.8 percent failing otoscopy, 7.5 percent failing tympanometry, and 25.3 percent failing pure-tone screening. Implications for medical and audiologic evaluation in the population are discussed.

Efficacy of audiologic rehabilitation for older adults.

Two intervention procedures for the rehabilitation of elderly adults with hearing impairment were evaluated: analytic auditory training and active listening training. Seventy-eight older adults with hearing loss served as subjects. Twenty-six subjects received no training, 26 received analytic training, and 26 received active listening training. The effectiveness of the audiologic rehabilitation programs was determined via measures of speech recognition, hearing handicap perception, and psychosocial function. Active listening was found to be an effective treatment for helping individuals with hearing impairment improve their auditory-visual recognition of speech in noise and improve certain aspects of their psychosocial functioning. Support for analytic speech recognition drills alone was not demonstrated.

A case of asymptomatic passage per-rectum of a fractured redundant peritoneal catheter from a ventriculo-peritoneal shunt.

Over 30 cases of perforation of the bowel have been described by intact peritoneal catheters of ventriculo-peritoneal and some lumbo-peritoneal shunts. Because of this risk it is advocated that redundant or free fractured or disconnected peritoneal catheters should if possible be removed from the abdomen; although we could find no reports of morbidity from such free fragments. We describe a case of extrusion per-rectum of a redundant fractured peritoneal catheter which it had not been possible to retrieve after a revision procedure.

Preferred Hearing Aid Response Characteristics Under Acoustic and Telecoil Coupling Conditions.

Telephone communication remains a major obstacle for hearing-impaired listeners. Even with the use of amplification, many hearing aid (HA) users report significant difficulty understanding telephone conversations. Although much effort has recently been focused on determining ideal HA performance for typical communication settings, less has been directed toward preferred HA responses during telephone coupling conditions. If one assumes that telecoil coupling strategies may require different HA performance characteristics because of line noise, filtering effects, coupling method, and output limitations imposed by the telephone system and receiver, then further study of listeners' preferred HA response characteristics under telecoil coupling conditions appears warranted.This study evaluated the preferred real ear aided response (REAR) for a group of hearing-impaired listeners under acoustic and telecoil conditions when coupled to a standard telephone receiver. Findings revealed that subjects preferred substantially more low-frequency gain than would be predicted using three popular prescriptive formulae. In general, a gradually rising to flat response was preferred by most of the hearing-impaired listeners. Implications for HA fitting and management will be discussed.

Cysto-peritoneal shunt infection with Trichosporon beigelii.

Infection is a frequent problem affecting cysto-peritoneal shunts, the usual causative organisms being Staphylococcus epidermidis and Staphylococcus aureus. Fungi are rarely isolated from such infections. We present the first report, as far as the authors are aware, of a case of Trichosporon beigelii shunt infection that responded to shunt removal and antifungal therapy.

Primary intracranial Hodgkin's disease. A case report and discussion.

We report here a case in which a frontotemporal meningeal tumor was found to be an isolated, apparently primary, deposit of nodular sclerosing Hodgkin's disease in an otherwise well man. The presentation of Hodgkin's disease as a primary, solitary intracranial lesion is rare; only 13 cases have been found in the world literature. The histological appearance of the tumor in the present case fulfills all the requirements for nodular sclerosing Hodgkin's disease according to current criteria of classification; the morphologic diagnosis is supported by appropriate immunohistochemical staining of the neoplastic cells for Leu M1 and LN2 markers, with absence of staining for the common leucocyte antigen. No recurrent local or disseminated disease has been manifest in a 14-month follow-up of the patient.

A closed- versus open-set measure of speech discrimination in normally hearing young and elderly adults.

This investigation sought to determine whether the pattern of performance differed between young and elderly normally hearing adults on a closed v. open-set discrimination task. The California Consonant Test was administered at 32 dB SL (re:SRT) to 20 young and 20 elderly normally hearing subjects under two conditions: one which required subjects to mark their response on a multiple choice answer form; and a second which required subjects to provide a one-word written response on a blank answer form. The only significant difference occurred within the young group between conditions (closed-set, open-set). The young group's speech discrimination was significantly better in the closed-set condition then in the open-set condition. No other differences were significant. The results question the concept of phonemic regression as a concomitant of ageing.

The effects of varying the number of cochlear implant electrodes on speech perception.

The purpose of this investigation was to evaluate the speech perception of a patient fitted with a multichannel processor under different electrode conditions. The subject was evaluated with the speech processor programmed with electrode arrays varying in number from one to nineteen. The results suggested that with an increased number of programmed electrodes, the subject's speech perception improved. Comparisons were also made among three speech processing strategies. The processor was programmed with: (1) one electrode pair that provided fundamental frequency information; (2) nineteen electrode paris that provided fundamental frequency plus second formant information (F0/F2); and (3) nineteen electrode paris that provided fundamental frequency plus first and second formant information (F0/F1F2). The subject did better with the F0/F2 strategy compared to the F0 strategy and best with the F0/F1F2 strategy.

Oligodendroglioma: an analysis of 42 cases.

This paper presents the clinical and pathological data obtained from 42 patients with oligodendroglioma diagnosed over a 20 year period at Addenbrooke's Hospital, Cambridge. In all cases the diagnosis was established unequivocally by histological examination. The principal conclusions of this study were: (1) the outcome was not as favourable as anticipated, nine patients dying within 1 year of diagnosis, and only 10 patients surviving 5 years, (2) age at the time of diagnosis was the single most important prognostic factor, patients under 45 years at diagnosis having a significantly greater survival time than older patients, (3) two other factors had a significantly adverse effect on prognosis, namely the presence of a focal neurological deficit at the time of diagnosis and the presence of nuclear pleomorphism in the tumour when examined histologically, (4) although cells containing glial fibrillary acidic protein were demonstrated in almost every tumour, their number and distribution did not appear to influence the prognosis.

Effect of norepinephrine and vasopressin on carotid sinus baroreceptor activity in the anesthetized rabbit.

Norepinephrine (NE) 10(-6) M or vasopressin (VP) 12.5 microU/ml were injected into the isolated carotid sinus of anesthetized rabbits. The sinus was exposed either to the arterial pressure or to a pressure controlled reservoir. Multifiber and single fiber recordings were made. Both NE and VP increased baroreceptor activity at all sinus pressures but decreased activity in a few fibers. The results are consistent with the drugs having their effects on smooth muscle fibers in the adventitia.

Telephone listening ability for hearing-impaired individuals.

Forty-five subjects with bilateral sensorineural hearing losses were divided into three groups (N = 15/group) based on the audiometric configuration of their test ear. The subjects were evaluated in three listening conditions by assessing their word discrimination ability by presenting stimuli at 86 dB SPL (simulating the output of a standard telephone handset ) and most comfortable loudness (MCL) (simulating the output of a telephone amplifier handset ). The three listening conditions were TDH-39 earphone, unaided telephone, and aided telephone with their personal hearing aid acoustically coupled to a telephone handset . Results indicated that subjects with precipitous hearing losses had similar word discrimination scores for all three listening conditions at 86 dB SPL and MCL. Subjects with gradual slope or flat hearing losses had similar word discrimination scores with a TDH-39 earphone, unaided telephone, and their hearing aids acoustically coupled to a telephone handset at 86 dB SPL. The subjects with gradual slope or flat losses also had similar word discrimination scores across the listening modes at MCL, but they had better word discrimination scores in all listening modes when the word lists were presented at MCL compared with 86 dB SPL.

The penetration of misonidazole and desmethylmisonidazole into brain tumours and other central nervous system tissues in man.

The concentration of drug after oral administration of 1 g misonidazole to patients undergoing neurosurgery has been studied in samples taken from intracerebral tumours, normal brain, cerebrospinal fluid and brain tumour cyst fluid. A total of 31 patients yielded samples at various times 2-8 h after drug administration. Results show a considerable range of tumour/plasma percentages but from about 2-5 h after drug administration this averaged between 65-80%. Normal brain and CSF showed similar good penetration but drug entry into cyst fluid was lower (30-50%). A further study with desmethylmisonidazole given to 11 additional patients showed a similar range of tumour penetration but lower concentrations in CSF and cyst fluid (10-20%). Low values were also seen in some but not all of the normal brain tissue samples. Necrotic tumour also had much lower concentrations than macroscopically viable tissue. These results are discussed in terms of their clinical relevance to sensitiser studies on patients with brain tumours with drugs of different lipophilicities.