Search Results
Results 401 - 450 of 1320
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Dreisbach Laura E - - 2005
The ability to discriminate the spectral shapes of complex sounds is critical to accurate speech perception. Part of the difficulty experienced by listeners with hearing loss in understanding speech sounds in noise may be related to a smearing of the internal representation of the spectral peaks and valleys because of ...
Tufts Jennifer B - - 2005
The purpose of this study was to determine whether the perceived sensory dissonance of pairs of pure tones (PT dyads) or pairs of harmonic complex tones (HC dyads) is altered due to sensorineural hearing loss. Four normal-hearing (NH) and four hearing-impaired (HI) listeners judged the sensory dissonance of PT dyads ...
Gifford René H - - 2005
In normal-hearing subjects, the slope of the growth-of-masking (GOM) function obtained in simultaneous masking when the masker frequency (f(m)) is much less than the signal frequency (f(s)) often changes from a value near 2.0 to a value near 1.0 at high levels. The purpose of the present study was to ...
Poncelet L - - 2006
This study evaluates the effects of a high-frequency hearing loss simulated by the high-pass-noise masking method, on the click-evoked brain stem-evoked potentials (BAEP) characteristics in dogs. BAEP were obtained in response to rarefaction and condensation click stimuli from 60 dB normal hearing level (NHL, corresponding to 89 dB sound pressure ...
Lopez-Poveda Enrique A - - 2005
Psychophysical estimates of basilar membrane (BM) responses suggest that normal-hearing (NH) listeners exhibit constant compression for tones at the characteristic frequency (CF) across the CF range from 250 to 8000 Hz. The frequency region over which compression occurs is broadest for low CFs. This study investigates the extent that these ...
Kaygusuz T Ozturk - - 2005
This study aimed to determine the effect of acute brucellosis on the auditory system. Forty-two patients with acute brucellosis were evaluated clinically, and with serological and audiological tests, before and after treatment. Hearing threshold averages were calculated at 11 different frequencies (250-8000 Hz) of the auditory airway, and statistical analysis ...
Mann David A - - 2005
Recent studies have shown that some clupeid fishes, including shad and menhaden, can detect ultrasound (sound with frequencies higher than 20 kHz) and actively avoid it. However, other clupeids, including sardines and anchovies, do not detect ultrasound. The hearing abilities of herring are of particular interest because of their commercial ...
Balatsouras D G - - 2005
OBJECTIVES: The aim of this study was to examine extended high-frequency (EHF) hearing in patients with acoustic trauma. DESIGN: A prospective, case-control study in a group of soldiers with acoustic trauma caused by shooting practice during basic training. SETTING: Tertiary referral centre. PARTICIPANTS: A total of 39 young soldiers hospitalized ...
Nousak J K - - 2005
The present study provides comparative evaluation of the ABR and MLR to 1 kHz brief tones in two groups of hearing-impaired subjects (noise-masked normally-hearing; and sensorineurally hearing-impaired adults), as well as a normally-hearing control group. Tones were presented at intensities from threshold to 80-90 dB nHL. The results of this ...
Jenstad Lorienne M - - 2005
Compression hearing aids have the inherent, and often adjustable, feature of release time from compression. Research to date does not provide a consensus on how to choose or set release time. The current study had 2 purposes: (a) a comprehensive evaluation of the acoustic effects of release time for a ...
Finneran James J - - 2005
A behavioral response paradigm was used to measure pure-tone hearing sensitivities in two belugas (Delphinapterus leucas). Tests were conducted over a 20-month period at the Point Defiance Zoo and Aquarium, in Tacoma, WA. Subjects were two males, aged 8-10 and 9-11 during the course of the study. Subjects were born ...
Vander Werff Kathy R - - 2005
OBJECTIVE: The purpose of this study was to examine the correlation between auditory steady-state response (ASSR) thresholds and behavioral thresholds in hearing-impaired adults with two common audiometric configurations. A second goal was to compare suprathreshold ASSR growth functions in these two subject groups and to determine whether these growth functions ...
Hine Jemma E - - 2005
Much research has shown that transient evoked otoacoustic emissions (TEOAEs) can successfully separate normally hearing and hearing impaired populations. However, this finding comes from TEOAEs recorded using conventional averaging at low stimulation rates. Presenting clicks according to maximum length sequences (MLSs) enables TEOAEs to be recorded at very high stimulation ...
Rosengard Peninah S PS Harvard-MIT Division of Health Sciences and Technology, Speech and Hearing Bioscience and Technology Program, Cambridge, Massachusetts 02139, USA. - - 2005
A loss of cochlear compression may underlie many of the difficulties experienced by hearing-impaired listeners. Two behavioral forward-masking paradigms that have been used to estimate the magnitude of cochlear compression are growth of masking (GOM) and temporal masking (TM). The aim of this study was to determine whether these two ...
Rance Gary - - 2005
Successful early intervention in children with permanent hearing loss requires assessment techniques that can accurately reflect the behavioral audiogram in infancy. This retrospective study compared auditory steady-state response (ASSR) findings from subjects tested in the first three months of life with subsequently obtained behavioral hearing levels. ASSR audiograms were established ...
Müller-Wehlau Matthias - - 2005
This study investigates the acoustic reflex threshold (ART) dependency on stimulus phase utilizing low-level reflex audiometry [Neumann et al., Audiol. Neuro-Otol. 1, 359-369 (1996)]. The goal is to obtain optimal broadband stimuli for elicitation of the acoustic reflex and to obtain objective determinations of cochlear hearing loss. Three types of ...
Lister Jennifer J - - 2005
Deficits in temporal resolution and/or the precedence effect may underlie part of the speech understanding difficulties experienced by older listeners in degraded acoustic environments. In a previous investigation, R. Roberts and J. Lister (2004) identified a positive correlation between measures of temporal resolution and the precedence effect, specifically across-channel gap ...
Kubli Lina R - - 2005
Harmonic complexes generated with positive or negative Schroeder-phases may result in differences in cochlear excitation, even though their long-term spectra and amplitudes are equal. As a measure of possible differences in cochlear excitation resulting from these harmonic complexes, thresholds and growth of the acoustic reflex were assessed in normal-hearing and ...
Karino Shotaro - - 2005
The effect of acute low-tone sensorineural hearing loss (ALHL) on the interaural frequency difference (IFD) required for perception of binaural beats (BBs) was investigated in 12 patients with unilateral ALHL and 7 patients in whom ALHL had lessened. A continuous pure tone of 30 dB sensation level at 250 Hz ...
Luts Heleen - - 2005
Two approaches to assess auditory steady-state responses (ASSR) are compared under similar test conditions: a monaural single-frequency technique with a detection method based on phase coherence (AUDERA), and a binaural multiple-frequency technique using the F-test (MASTER). ASSR thresholds at four frequencies were assessed with both methods in both ears of ...
Hunter Eric J - - 2005
Frequency and intensity ranges in voice production by trained and untrained singers were superimposed onto the average normal human hearing range. The vocal output for all subjects was shown both in Voice Range Profiles and Spectral Level Profiles. Trained singers took greater advantage of the dynamic range of the auditory ...
Okamoto Yasuhide - - 2005
Mitochondrial dysfunction in the cochlea is thought to be an important cause of sensorineural hearing loss. Recently, we have established a novel rat model with acute hearing impairment caused by exposure to the mitochondrial toxin 3-nitropropionic acid (3-NP) to analyze the mechanism of cochlear mitochondrial dysfunction. Both permanent and temporary ...
Kong Ying-Yee - - 2005
Speech recognition in noise and music perception is especially challenging for current cochlear implant users. The present study utilizes the residual acoustic hearing in the nonimplanted ear in five cochlear implant users to elucidate the role of temporal fine structure at low frequencies in auditory perception and to test the ...
Wagener Kirsten Carola - - 2005
Speech intelligibility measurements strongly depend on several procedural parameters. In order to obtain comparable results from different test procedures, these parameters must be investigated as to which should be standardized and which could be set freely. This study investigates the influence of noise level, noise type, and presentation mode on ...
Wysocki Lidia Eva - - 2005
Our current knowledge on sound detection in fishes is mainly based on data acquired under quiet laboratory conditions. However, it is important to relate auditory thresholds to background noise in order to determine the signal-detecting abilities of animals in the natural environment. We investigated the influence of two noise levels ...
Rose Marina M - - 2005
We examined the relationship between the fission boundary (FB) at which a sequence of pure tones alternating between two frequencies cannot be heard as two separate streams and the frequency difference limen (FDL), using normally hearing subjects and subjects with cochlear hearing loss. The stimuli used in the two tasks ...
Lazarus Hans - - 2005
Recognition of acoustic signals when perception is subject to interference from noise has already been extensively studied. In this study the influence of hearing protectors (HP) (plugs, muffs) and hearing loss on signal recognition is examined. Different spectrums and levels of the noise are also included. The test results are ...
Olszewski Jurek - - 2005
OBJECTIVES: The aim of the study was to assess the influence of short-term impulse noise on the size and dynamics of temporary threshold shift, which precedes permanent threshold shift, i.e. noise-induced hearing loss. It was hoped to use the findings for preventive activities. MATERIALS AND METHODS: The study included 80 ...
Samadi Daniel S - - 2005
Mutagenesis of the POU-domain gene Brn4/Pou3f4 causes defects in the cochlear duct, semicircular canal, temporal bone and stapes footplate. The footplate defect suggested a middle-ear conductive component to the hearing loss associated with this mutation. This was examined by measuring velocity transfer functions at the umbo of wild type and ...
Neubauer Heinrich - - 2004
For signal detection and identification, the auditory system needs to integrate sound over time. It is frequently assumed that the quantity ultimately integrated is sound intensity and that the integrator is located centrally. However, we have recently shown that absolute thresholds are much better specified as the temporal integral of ...
Oktay M Faruk - - 2004
BACKGROUND: The effects of radio frequency (RF) and microwave radiation on humans have been the subject of continuous investigation. Clinical investigations related to occupational RF/microwave exposure have been reported by investigators (1). Since one of the major groups occupationally exposed to RF and microwave radiation includes those working in radio ...
De Leenheer Els M R - - 2004
Members of a Dutch DFNA13/COL11A2 family were evaluated with pure tone audiometry, stapedial reflexes, otoacoustic emissions, loudness scaling, difference limen for frequency, gap detection, and speech perception in quiet and noise. The tone audiometry showed a predominant loss for the low and middle frequencies, with only a few otoacoustic emissions ...
Heffner Rickye S - - 2004
This review discusses hearing performance in primates and selective pressures that may influence it. The hearing sensitivity and sound-localization abilities of primates, as indicated by behavioral tests, are reviewed and compared to hearing and sound localization among mammals in general. Primates fit the mammalian pattern with small species hearing higher ...
Coleman Mark N - - 2004
The auditory region contains numerous structures that have proven useful for phylogenetic classification at various taxonomic levels. However, little work has been done in primates relating differences in morphology to variations in hearing performance. This study documents anatomical and physiological distinctions within primates and begins to address the functional and ...
Sandor Patrick M B - - 2004
BACKGROUND: Future fighter aircraft will include three-dimensional sound signals as part of the human-machine interface. The reduction in cerebral vascular flow associated with maneuvering acceleration (+Gz) may affect a pilot's ability to perceive and interpret such aural cues. We hypothesized that vascular deprivation along the cochlea produced by +Gz would ...
Oxenham Andrew J AJ Research Laboratory of Electronics, and Harvard-MIT Division of Health Sciences and Technology, Speech and Hearing Bioscience and Technology Program, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. - - 2004
The presence of cochlear-based compression at low frequencies was investigated by measuring phase effects in harmonic maskers. In normal-hearing listeners, the amount of masking produced depends strongly on the phase relationships between the individual masker components. This effect is thought to be determined primarily by properties of the cochlea, including ...
Lentz Jennifer J - - 2004
The effect of onset asynchrony on discrimination of spectral shape was evaluated for hearing-impaired and normal-hearing listeners. Stimuli were the sum of four tones equally spaced on a logarithmic frequency scale. The standard stimulus had tones of equal amplitude, and the signal stimulus had two adjacent components increased in level, ...
Smith Michael E - - 2004
Mammals exposed to loud aerial sounds exhibit temporary threshold shifts (TTS) that are linearly related to increases of sound pressure above baseline hearing levels. It was unknown if this relationship held true for aquatic ectotherms such as fishes. To test this linear threshold shift hypothesis (LINTS) in fishes, we examined ...
Begall Sabine - - 2004
Learning curves and behavioural audiograms of subterranean, socially living coruros (Spalacopus cyanus) were obtained using a positive reinforcement conditioning procedure. The individually varying audiograms revealed best hearing at frequencies between 1.25 and 1.6 kHz, which corresponds with the common pattern established in subterranean rodents studied so far. However, the broad ...
Mauermann Manfred - - 2004
Hearing thresholds measured with high-frequency resolution show a quasiperiodic change in level called threshold fine structure (or microstructure). The effect of this fine structure on loudness perception over a range of stimulus levels was investigated in 12 subjects. Three different approaches were used. Individual hearing thresholds and equal loudness contours ...
Bruce Ian C - - 2004
Spectral enhancement is now being used in many hearing aids in an attempt to compensate for broadened cochlear filtering. However, spectral enhancement may be counteracted by multiband-compression algorithms designed to compensate for the reduced dynamic range of the impaired cochlea. An alternative scheme for spectral enhancement, contrast-enhancing frequency shaping (CEFS), ...
Luts Heleen - - 2004
OBJECTIVE: To report on clinical experience using dichotic multiple-stimulus auditory steady-state responses (ASSRs) as an objective technique to estimate frequency-specific hearing thresholds in hearing-impaired infants. METHODS: A comparison was made between the click-evoked auditory brainstem response (ABR), auditory steady-state responses and behavioral hearing thresholds (BHTs). Both ears of 10 infants ...
Ahmed Hafiz O - - 2004
OBJECTIVE: To determine the accuracy of questions in identifying subjects occupationally exposed to high noise level and those with hearing loss using noise dosimeter and pure-tone air conduction audiometry as the gold standards. DESIGN: A cross-sectional study involving 259 noise-exposed workers selected randomly from two factories in Eastern Saudi Arabia. ...
Moore Brian C J - - 2004
The identification of nonsense syllables in quiet and in three types of background (babble, cafeteria and single female speaker) was measured using four hearing aid compression algorithms differing in attack and release time constants, and using linear amplification. The speech level was always 65 dB SPL. The compression algorithms, which ...
Mackersie Carol L - - 2004
The purpose of this study was to compare threshold-matched ears with and without suspected cochlear dead regions in terms of the speech perception benefit from high-frequency amplification. The Threshold Equalizing Noise Test (TEN) was used to assess the presence of dead regions. Speech perception was measured while participants were wearing ...
Martínez I - - 2004
Human hearing differs from that of chimpanzees and most other anthropoids in maintaining a relatively high sensitivity from 2 kHz up to 4 kHz, a region that contains relevant acoustic information in spoken language. Knowledge of the auditory capacities in human fossil ancestors could greatly enhance the understanding of when ...
Moore Brian C J - - 2004
Buus and Florentine [J. Assoc. Res. Otolaryngol. 3, 120-139 (2002)] have proposed that loudness recruitment in cases of cochlear hearing loss is caused partly by an abnormally large loudness at absolute threshold. This has been called "softness imperception." To evaluate this idea, loudness-matching functions were obtained using tones at very ...
Maj Jean-Baptiste - - 2004
OBJECTIVE: The performance of an adaptive beam-former in a 2-microphone, behind-the-ear hearing aid for speech understanding in noisy environments was evaluated. Physical and perceptual evaluations were carried out. This was the first large-scale test of a wearable real-time implementation of this algorithm. The main perceptual research questions of this study ...
Moore Brian C J - - 2004
For normally hearing subjects, harmonic complex tones that give "peaky" waveforms on the basilar membrane (Schroeder-positive phase, sine phase or cosine phase) lead to less forward masking than complex tones that give less peaky waveforms (Schroeder-negative phase or random phase), but have the same power spectrum. This difference has been ...
Brittan-Powell Elizabeth F - - 2004
Auditory feedback influences the development of vocalizations in songbirds and parrots; however, little is known about the development of hearing in these birds. The auditory brainstem response was used to track the development of auditory sensitivity in budgerigars from hatch to 6 weeks of age. Responses were first obtained from ...
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