INTRODUCTION: Although single hearing protection devices such as earplugs or earmuffs are known to degrade sound localization, little is known about localization accuracy in double-hearing-protection conditions where both earplugs and earmuffs are worn at the same time. METHODS: Listeners wearing earplugs, earmuffs, or a combination of earplugs and earmuffs were ...

Efforts to study the social acoustic signaling behavior of delphinids have traditionally been restricted to audio-range (<20 kHz) analyses. To explore the occurrence of communication signals at ultrasonic frequencies, broadband recordings of whistles and burst pulses were obtained from two commonly studied species of delphinids, the Hawaiian spinner dolphin (Stenella ...

Audiometric measurements are traditionally made in dB HL, which by definition are specified relative to the sound pressure level (SPL) in a coupler. Real-ear dB SPL is then estimated by applying an average ear transform to the coupler value. However, individual variation in ear canal acoustics and variations in transducer ...

Ototoxicity of salicylate is accompanied by a temporary hearing loss and tinnitus and has therefore been used to study tinnitus in animal models. Salicylate induced elevated central auditory activity has been interpreted as a correlate of tinnitus. Whether this elevated activity in the central auditory system is due to an ...

A study of click-evoked otoacoustic emissions (CEOAEs) elicited at stimulation intensities from 35 to >80 dB was carried out by recurrence quantification analysis on signals from both normal and hearing-impaired subjects. In normal subjects, a clear scaling of determinism with increasing stimulation intensity was observed in the click intensity range ...

Potentially hazardous noise levels are generated in the course of major orthopaedic surgery. The risk to staff is probably real but very small. We used a sound level meter to record maximum and mean levels and found peak values which exceeded 100 dB(A). If sustained, there is a possibility of ...

Otophysine fishes are characterized by Weberian ossicles connecting the swimbladder to the ear acoustically. In order to determine the degree to which these ossicles contribute to auditory sensitivity, the tripus was unilaterally or bilaterally extirpated in goldfish and hearing thresholds determined. The auditory evoked potential (AEP) recording technique was used ...

Difference limens for the fundamental frequency (F0) of complex tones (DLCs) were measured for four normally hearing subjects and three subjects with cochlear hearing loss. The nominal F0 was 100, 200 or 400 Hz. The two tones to be compared contained either low resolved harmonics (RES), harmonics with intermediate resolvability ...

The "active process" is a term used to describe amplification and filtering processes that are essential for obtaining the exquisite sensitivity of hearing organs. Understanding the components of the active process is important both for our understanding of the normal physiology of hearing and because perturbations of the cochlear amplifier ...

Patients with steeply sloping hearing losses of cochlear origin may exhibit enhanced difference limens for frequency (DLFs) near the cut-off frequency (Fc) of their hearing loss. This effect has been related to observations in deafened animals of an over-representation of Fc in the primary auditory cortex. However, alternative interpretations in ...

Distortion product otoacoustic emission (DPOAE) suppression measurements were made in 20 subjects with normal hearing and 21 subjects with mild-to-moderate hearing loss. The probe consisted of two primary tones (f2, f1), with f2 held constant at 4 kHz and f2/f1 = 1.22. Primary levels (L1, L2) were set according to ...

Intensity difference limens (DLs) were measured in users of the Nucleus 22 and Clarion v1.2 cochlear implants and in normal-hearing listeners to better understand mechanisms of intensity discrimination in electric and acoustic hearing and to evaluate the possible role of neural adaptation. Intensity DLs were measured for three modes of ...

OBJECTIVES: The study goal was to determine whether a single Space Shuttle mission can induce decrements in astronaut hearing. Study design We retrospectively compared audiogram information obtained from Space Shuttle astronauts at 10 days preflight, day of return (R + 0), 3 days after landing return (R + 3), and ...

Effective objective testing methodology is needed for early detection of the effects of ototoxicity on hearing in patients. The requirements for such testing include responses that are: 1) reliable across test sessions; 2) sensitive to ototoxic change ( > 8 kHz), and 3) recordable in a time-efficient manner. Auditory brainstem ...

Improving the signal-to-noise ratio (SNR) for individuals with hearing loss who are listening to speech in noise provides an obvious benefit. Although binaural hearing provides the greatest advantage over monaural hearing in noise, some individuals with symmetrical hearing loss choose to wear only one hearing aid. The present study tested ...

This article details a new method that has been developed to transmit auditory and visual information to people who are deaf or hard of hearing. In this method, ordinary fluorescent lighting is modulated to carry an assistive data signal throughout a room while causing no flicker or other distracting visual ...

Clinical applications of transient evoked otoacoustic emission (TEOAE) measures began in 1989 at Mayo Clinic Rochester. Normative data indicates: a) greater TEOAE level for women and right ears beginning in the teen years, b) mean TEOAE levels remain relatively stable through the first seven decades of life, c) between subject ...

This paper describes the second phase of a study to determine test-retest reliability of hearing thresholds using a computer-automated technique with ER-4B Canal Phone insert earphones. The first phase documented reliable hearing thresholds in 20 normal-hearing individuals. For this second phase, 20 individuals with cochlear hearing loss completed the same ...

The differences in spectral shape resolution abilities among cochlear implant (CI) listeners, and between CI and normal-hearing (NH) listeners, when listening with the same number of channels (12), was investigated. In addition, the effect of the number of channels on spectral shape resolution was examined. The stimuli were rippled noise ...

We determined the audiograms of two short-tailed fruit bats (Carollia perspicillata), 18-g phyllostomids from Central and South America. For testing, we used a conditioned suppression/avoidance procedure with a fruit juice reward. At an intensity of 60 dB SPL, the hearing of C. perspicillata extends from 5.2 to 150 kHz, showing ...

The effects of intense white noise (158 dB re 1 microPa for 12 and 24 h) on the hearing abilities of two otophysine fish species--the nonvocal goldfish Carassius auramus and the vocalizing catfish Pimelodus pictus--were investigated in relation to noise exposure duration. Hearing sensitivity was determined utilizing the auditory brainstem ...

The auditory sensitivities of the orange-fronted conure (Aratinga canicularis) were examined in relation to the spectral characteristics of its vocalizations. Absolute thresholds, masked thresholds, frequency difference limens, and intensity difference limens for pure tones were obtained using psychoacoustic techniques. In general, hearing abilities are similar to those found in many ...

The ability to discriminate between sounds with different spectral shapes was evaluated for normal-hearing and hearing-impaired listeners. Listeners discriminated between a standard stimulus and a signal stimulus in which half of the standard components were decreased in level and half were increased in level. In one condition, the standard stimulus ...

We investigated the amount of fine-structure in the audiograms of patients with Menière's disease. Both ears (often an affected and an unaffected ear) were investigated. Data are presented from 39 ears of 21 patients with hearing thresholds varying from about 0 to 70 dB HL. The fine-structure was measured in ...

The underwater hearing sensitivity of a striped dolphin was measured in a pool using standard psycho-acoustic techniques. The go/no-go response paradigm and up-down staircase psychometric method were used. Auditory sensitivity was measured by using 12 narrow-band frequency-modulated signals having center frequencies between 0.5 and 160 kHz. The 50% detection threshold ...

Conventional bone conduction transducers, which are relatively large, suffer from poor performance at low frequencies. A new type of electro-dynamic transducer, the balanced electromagnetic separation transducer (BEST), was developed to improve the performance of the conventional transducers. By using a balanced suspension principle, the quadratic distortion forces, as well as ...

The crepuscular nymphalid butterfly Manataria maculata was studied in Monteverde cloud forest, Costa Rica, during the dry season reproductive diapause. M. maculata has ears in the form of Vogel's organs located near the base of the forewings. Its behaviour in response to bursts of ultrasonic pulses (26 kHz, 110 dB ...

Noise of such a high level that it can result in hearing deterioration is an inherent characteristic of military flying. Susceptibility to hearing impairment was studied using 51 Finnish Air Force military personnel as subjects. The test persons flew missions on a British Aerospace Hawk 51 advanced jet trainer, Boeing ...

Auditory brainstem response (ABR) and standard behavioral methods were compared by measuring in-air audiograms for an adult female harbor seal (Phoca vitulina). Behavioral audiograms were obtained using two techniques: the method of constant stimuli and the staircase method. Sensitivity was tested from 0.250 to 30 kHz. The seal showed good ...

A piezoelectric sprayer was recently developed for precision release of odor stimuli in olfactory research. The device replaces conventional dispensers used to release semiochemicals in studies of moth flight toward sources. However, the device generates high-frequency sounds in the range that some moths can hear. Ultrasound from the standard set-up ...

The calls of five syntopic species of Neoconocephalus varied significantly in their spectral composition. The center-frequency of the narrow-band low-frequency component varied from 7 kHz to 15 kHz among the five species. Hearing thresholds, as determined from whole nerve recordings, did not vary accordingly among the five species but were ...

In this study, the authors determined the characteristics of noise-induced hearing loss (NIHL) and its association with hearing-loss-related symptoms (HLRSs) among workers at an oil refinery in Taiwan. Workers from the refinery (N = 384) who had chronic noise exposure (range = 73 to 89 dBa; mean = 81.2, standard ...

Speech recognition in noise improves when speech and noise sources are separated in space. This benefit has two components whose effects are strongest in different frequency regions: (1) interaural level differences (e.g., head shadow), which are largest at higher frequencies, and (2) interaural time differences, which have their greatest contribution ...

The use of high stimulus rates has the potential to improve the electrocochleogram's (ECochG) sensitivity and specificity in endolymphatic hydrops and Menière's disease, but is currently hindered by the absence of an acceptable normative database. In response, this study recorded click-evoked ECochG tracings from 51 normal-hearing subjects (102 ears), between ...

The Drosophila auditory system is presented as a powerful new genetic model system for understanding the molecular aspects of development and physiology of hearing organs. The fly's ear resides in the antenna, with Johnston's organ serving as the mechanoreceptor. New approaches using electrophysiology and laser vibrometry have provided useful tools ...

In this study, an original psychometric procedure was used in order to characterize in more detail than in previous studies the different perceptual components of tinnitus, i.e. auditory sensations which are perceived in the absence of a corresponding external acoustic stimulus. Ten subjects with chronic tinnitus were asked to rate ...

The underwater hearing sensitivity of an 18-year-old male Pacific walrus was measured in a pool by using a go/no-go response paradigm and the up-down staircase method. Auditory sensitivity was measured using narrow-band, frequency-modulated signals (1500 ms duration) with center frequencies ranging from 0.125 to 15 kHz. The resulting underwater audiogram ...

In this study, an adaptive procedure for categorical loudness scaling is introduced and evaluated. The procedure adjusts the presentation levels to the subject's individual auditory dynamic range without employing any premeasurement and presents levels in randomized order. The procedure has been named "Oldenburg-ACALOS" (Oldenburg-Adaptive CAtegorical LOudness Scaling). It was evaluated ...

An adaptive beamformer for behind-the-ear dual-microphone hearing aids has been optimized for speech intelligibility enhancement in the presence of disturbing sounds or noise. The noise reduction approach is based on the scheme presented by Vanden Berghe and Wouters (1998). A real-time implementation of the signal processing is realized in Audallion, ...

The view seems to prevail that the frequency range of hearing is determined by the properties of the outer and middle ears. We argue that this view is an oversimplification, in part because the reactive component of cochlear input impedance, which affects the low-frequency sensitivity of the cochlea, is neglected. ...

People with high-frequency sensorineural hearing loss differ in the benefit they gain from amplification of high frequencies when listening to speech. Using vowel-consonant-vowel (VCV) stimuli in quiet that were amplified and then low pass filtered with various cutoff frequencies, Vickers et aL [J. Acoust. Soc. Am. 110, 1164-1175 (2001)] found ...

We determined the audiogram of Phyllostomus hastatus (the greater spear-nosed bat), a large, omnivorous American leaf-nosed bat native to Central and South America. A conditioned suppression/avoidance procedure with a fruit juice reward was used for testing. At an intensity of 60 dB sound pressure level (SPL re 20 microN/m(2)), the ...

The auditory brainstem response (ABR) was recorded in adult budgerigars (Melopsittacus undulatus) in response to clicks and tones. The typical budgerigar ABR waveform showed two prominent peaks occurring within 4 ms of the stimulus onset. As sound-pressure levels increased, ABR peak latency decreased, and peak amplitude increased for all waves ...

Fluctuating asymmetry in bilaterally placed sensory structures of insects may be considered maladaptive; natural selection should favour a symmetrical system. Among bushcrickets or katydids, threshold hearing sensitivity is, in part, dependent on the size of the auditory spiracle in the prothorax. We tested the degree of natural asymmetry in the ...

Hearing-impaired listeners often suffer from supra-threshold speech perception deficits. One such deficit is reduced frequency selectivity. We applied a speech enhancement scheme that incorporated spectral expansion in an attempt to reduce the effects of this deficit. The speech processing could contain up to three stages, a first in which the ...

It is not known to what extent the entire saccule contributes to overall hearing sensitivity in any fish species. Here we report directional and frequency sensitivity in a teleost fish (Dormitator latifrons) and effects of unilateral and bilateral removal of saccular otoliths on its hearing sensitivity. The fish had different ...

OBJECTIVE: As part of a large clinical trial that compared three hearing aid circuits using several evaluation methods, judgments about quality of listening experiences were sought from all subjects. Three dimensions were examined: loudness, noise interference and overall liking (quality). DESIGN: Eight Audiology units in VA Medical Centers participated. Three ...

The C57BL/6 mouse has long been considered, in scores of published studies, as a model of early adult-onset, progressive sensorineural hearing loss (presbycusis). The auditory brainstem response (ABR) has most often been used in these studies as a measure of functional loss. Whereas the ABR measures the response to a ...

OBJECTIVE: The goal of this study was to determine whether tonebursts gated on and off using a nonlinear, exact-Blackman-gating function would be a more frequency-specific stimulus for auditory brain stem response audiometry than the more traditional 2-1-2 cycle linearly gated toneburst. DESIGN: Toneburst ABRs were recorded in 10 adults with ...

OBJECTIVE: The purpose of this study was to determine the influence of the compression time constants in a multi-channel compression hearing aid on both subjectively assessed speech intelligibility and sound quality in realistic binaural acoustical situations for normal-hearing and hearing-impaired listeners. DESIGN: A nonlinear hearing aid with 15 independent compression ...