Factors that influence the benefit from amplification in the elderly.

Many factors have been proposed as potential determinants of the benefit that an individual receives from wearing a hearing aid. In this study, to quantify their relative importance, 54 individuals with symmetrical sensorineural hearing impairment were presented with and without simulated hearing aid characteristics on two measures of disability that were based on identifying words in sentences. Benefit was defined as the difference between the percentage of correct scores with and without the aid characteristics switched into the audio circuit.

The role of non-auditory factors in measured and self-reported disability.

The effect of age per se on auditory disability in relation to other non-auditory factors, including personality and IQ, is unclear because of the close link with hearing threshold level. Auditory disability may be assessed in terms of either performance or self-report. It was measured using two tasks identifying words in sentences: (1) sentence identification in noise for spatially separated signal sources, and (2) identification of sensible and nonsensical sentences given at normal and artificially accelerated rates.

Hearing disability in the elderly.

Hearing disability increases with hearing impairment and impairment increases with age, especially for persons over the age of 50 years. Older subjects also appear to display an excess disability, additional to that expected from impairment. This paper quantifies the excess disability and its dependence on sex and socio-economic factors.

Epidemiological profile of hearing impairments: the scale and nature of the problem with special reference to the elderly.

The nature and scale of services for hearing-impaired people should be formed in the light of the demographic profile of the hearing-impaired. This paper furnishes data for three elements of that profile: the number of hearing-impaired people in England and Wales, the increase in the number of hearing-impaired that might be expected given the growth of the elderly population in England and Wales, and the major factors that influence use of hearing services at present. The combination of reliable prevalence data (1) with demographic information (2) gives good estimates of the numbers of hearing-impaired people and their age distribution.

The contribution of central auditory factors to auditory disability.

Auditory disability increases with both hearing threshold level and age. It is often suggested that some or most of the age effect in auditory disability is underpinned by deficits in central auditory function. A sample of 240 individuals aged between 50 and 75 years was examined to provide a balance across the major variables of hearing level and age.

Degradations in frequency and temporal resolution with age and their impact on speech identification.

Measures of frequency resolution were obtained in two population samples. The first sample comprised 1764 subjects with various degrees of sensorineural hearing impairment aged from 17 to 80 years. The second sample included 229 subjects with ages between 50 and 75 years, balanced to avoid confounding the effects of impairment and age.

Longitudinal study of hearing.

Our knowledge of the progression and aetiology of hearing impairments is mainly inferred from cross-sectional studies of populations or individual case studies of relatively rare conditions. Longitudinal studies of carefully stratified samples enable scientific analysis of these two aspects of the ageing auditory system and also provide much needed incidence data on the basis of which to plan comprehensive hearing services. This preliminary paper using data from two studies over relatively short periods (between 2-4.

The prevalence of hearing impairment and reported hearing disability among adults in Great Britain.

Estimates for the prevalence of self-reported hearing disability and measured hearing impairment as a function of age in the adult population of Great Britain (GB) are reported from two 2-stage surveys. The main study was conducted in Cardiff, Glasgow, Nottingham and Southampton, with rigorous audiological assessment at the second stage. A supplementary study used a sample representative of GB with simplified domiciliary audiological assessments.

Verification of a new test of endolymphatic hydrops.

A new objective test of endolymphatic hydrops has been described previously. The test uses auditory brain-stem response (ABR) techniques to estimate the basilar membrane travelling wave velocity (TWV). The underlying hypothesis is that raised pressure in the scala media will lead to an increase in the stiffness of the basilar membrane and that this will give rise to a travelling wave velocity that is greater than normal.

Another role for melanocytes: their importance for normal stria vascularis development in the mammalian inner ear.

The stria vascularis of the mammalian cochlea is composed primarily of three types of cells. Marginal cells line the lumen of the cochlear duct and are of epithelial origin. Basal cells also form a continuous layer and they may be mesodermal or derived from the neural crest.

A pseudo free-field measure of auditory disability.

Conventional measures of auditory disability via speech identification scores are usually monaural, or occasionally, diotic. Circumstances of everyday listening usually contain stereophonic (dichotic) cues, whilst such listening situations can be tested in a free field environment they are difficult to standardize and calibrate. A procedure has been developed by recording the signals from two Zwislocki couplers in a KEMAR mannikin to produce a headphone-presented set of speech material containing the important dichotic cues present in free field listening.

Effects of posture and age on tympanic membrane displacement measurements.

This study used changes in posture to investigate the transmission of cerebro-spinal fluid (CSF) pressure changes to the cochlear fluids in subjects falling into two age groups. Results were obtained from 32 subjects: 16 aged 19 to 32 years and 16 aged between 40 and 63. Measurements were made with the subject sitting upright and then at 63 degrees to the vertical, using a technique which measures displacement of the tympanic membrane in response to acoustic stimulation of the stapedial reflex.

Changes in the masked thresholds of brief tones produced by prior bursts of noise.

Thresholds were measured for 5-ms 1-kHz tones masked by synchronous bursts of noise containing a spectral notch centered on the signal frequency. Thresholds were reduced by prior exposure to a 200-ms burst of a 'priming stimulus' which had the same spectral shape as the masker. The masking release was greatest for notch widths extending between 20-30% above and below the signal frequency.

The IHR-McCormick Automated Toy Discrimination test--description and initial evaluation.

McCormick's Toy Discrimination test allows a skilled audiologist to obtain word discrimination thresholds in quiet from children with mental ages of 2 years and above. A semi-automatic version of the test has been developed and evaluated by testing the hearing of 46 children and five adults. The equipment for the new version of the test both produces the stimuli and scores the responses, thereby reducing the burden on the tester.

Relative benefits of stepped and constant bore earmoulds: a crossover trial.

Twenty-one first-time hearing aid candidates took part in a crossover trial which compared a stepped earmould of the 8CR design with a standard constant-bore earmould, each fitted to a low-powered National Health Service behind-the-ear hearing aid. Before fitting the aid, and also after 2-week trials with each earmould, aided speech-in-noise discrimination scores were obtained, along with subjective ratings according to a series of descriptive scales, and overall preference for one or other of the aids. Aided speech-in-noise scores were, on average, 2.

The clinical assessment of obscure auditory dysfunction--1. Auditory and psychological factors.

We define obscure auditory dysfunction (OAD) as the clinical presentation of reported difficulty understanding speech in the presence of noise accompanied by clinically "normal" hearing thresholds, and no other obvious cause. The term deliberately avoids particular pathophysiological connotations. A detailed characterization of such patients was undertaken as the basis for future diagnosis and management of OAD by clinicians.

Staffing and structure for paediatric audiology services in hospital and community units.

The component functions of a paediatric audiology service are outlined on the basis of the main broad categories of patient and their requirements, as seen from a 'good practice' standpoint; a service structure is offered in terms of patient flow. This leads to a distinction between the small, specifically medical requirement, and the large, specifically audiological testing requirement. Indications are given of the scale of audiology requiring to be done by community staff not specializing in audiology.

Limitations on insertion gains with vented earmoulds imposed by oscillatory feedback.

When an earmould is vented, either to relieve sensations of blockage or to modify the frequency response of a hearing aid system, the gain setting at which feedback occurs is lowered. Although this principle is widely appreciated, the typical gains at which feedback occurs have received little systematic study and vented earmoulds are still prescribed on largely rule-of-thumb, or trial and error basis. In a laboratory study on a KEMAR mannikin the effects for hearing aids with gains up to 64 dB were studied.

Neuronal responses to amplitude-modulated and pure-tone stimuli in the guinea pig inferior colliculus, and their modification by broadband noise.

Neuronal responses were recorded to pure and to sinusoidally amplitude-modulated (AM) tones at the characteristic frequency (CF) in the central nucleus of the inferior colliculus of anesthetized guinea pigs. Temporal (synchronized) and mean-rate measures were derived from period histograms locked to the stimulus modulation waveform to characterize the modulation response. For stimuli presented in quiet, the modulation gain at low frequencies of modulation (approx less than 50 Hz) was inversely proportional to the neuron's mean firing rate in response to both the modulated stimulus and to a pure tone at an equivalent level.

High-frequency monitoring using an electrostimulation audiometer.

Electrostimulation audiometry can provide high-frequency bone-conduction threshold measurements. To evaluate the use of such an audiometer in monitoring hearing, the following areas were investigated. (1) The variability and repeatability of threshold measurements.

Modeling the perception of concurrent vowels: vowels with the same fundamental frequency.

The ability of listeners to identify pairs of simultaneous synthetic vowels has been investigated in the first of a series of studies on the extraction of phonetic information from multiple-talker waveforms. Both members of the vowel pair had the same onset and offset times and a constant fundamental frequency of 100 Hz. Listeners identified both vowels with an accuracy significantly greater than chance.

Differential diagnostic potential of otoacoustic emissions: a case study.

An 11-year-old boy was identified as having a profound sensorineural hearing loss accompanied by clear click-evoked otoacoustic emissions. Further diagnostic testing by means of electrocochleography and auditory brainstem responses indicated a predominantly retrocochlear disorder with good cochlear function. However, radiological investigation ruled out the presence of any material space-occupying lesion.

Clinical methods for the objective estimation of loudness discomfort level (LDL) using auditory brainstem responses in patients.

Our previous work showed that the slope of the JV latency/intensity function can be used to estimate the loudness discomfort level (LDL). In this study, the previous work was repeated using normal subjects and patients whose LDL was unknown at the time of test. The results showed that the original model still applied.