Recovery of auditory threshold following exposures to a pure tone and white noise.

1992 ◽  
Vol 91 (4) ◽  
pp. 2381-2382
Author(s):  
I. M. Young ◽  
L. D. Lowry ◽  
H. Menduke
Keyword(s):  
White Noise ◽  
Pure Tone ◽  
Auditory Threshold

Masked and unmasked pure tone detection thresholds of a harbour seal listening in air

1991 ◽  
Vol 69 (8) ◽  
pp. 2059-2066 ◽  
Author(s):  
J. M. Terhune
Keyword(s):  
White Noise ◽  
Pure Tone ◽  
Phoca Vitulina ◽  
Harbour Seal ◽  
Optimal Conditions ◽  
Vascular Changes ◽  
Detection Thresholds ◽  
Noise Masker ◽  
Auditory Systems ◽  
Tone Detection

In-air pure tone detection thresholds of a harbour seal (Phoca vitulina) were measured using behavioural psychophysical techniques. Thresholds dropped from about 70 dB re 20 μPa at 0.1 kHz to about 35 dB re 20 μ Pa at 4 kHz and then increased to about 45 dB re 20 μPa at 16 kHz. Increased sensitivities at 2 and 8 kHz, which have been reported in other pinnipeds, were not evident. In-air intensity detection thresholds averaged 32 dB above their underwater counterparts (1–16 kHz). Masking studies found the critical ratios at 0.25, 0.5, and 1 kHz to be 24, 15, and 21 dB, respectively (white noise masker). From 0.2 to 1.5 kHz, bandwidths 20 dB below the level of pure tone maskers were 0.16–0.18 kHz. Circumstantial evidence suggests the possibility that blood vascular changes associated with diving might also influence the sensitivity of the auditory systems of seals. Under optimal conditions, a pup's airborne cries may be detected by its mother at ranges of 1 km or more.

Potentials evoked by sound in the auditory cortex of the cat

1961 ◽  
Vol 200 (6) ◽  
pp. 1219-1225 ◽  
Author(s):  
Robert J. Gumnit ◽  
Robert G. Grossman
Keyword(s):  
Auditory Cortex ◽  
White Noise ◽  
Pure Tone ◽  
Evoked Response ◽  
Moderate Intensity ◽  
Positive Potential ◽  
Positive Wave ◽  
Natural Sleep ◽  
Negative Shift ◽  
Long Duration

The electrical responses of the auditory cortex of awake, loosely restrained cats were examined with chronically implanted calomel electrodes and d-c recording systems. Stimulation with a single click evoked a complex triphasic response in which a large surface positive potential (duration, 250 msec) followed the classic diphasic response. This second positive wave was absent in natural sleep and under light barbiturate anesthesia. A similar late positive wave of long duration, evoked by a flash of light, was found in the visual cortex. A rapid series of clicks evoked a surface negative shift which was maintained for the duration of the stimulus. A tone or white noise presented for several seconds evoked a negative shift of the same general form. A pure tone of moderate intensity presented simultaneously with a click greatly enhanced the click-evoked response. White noise of moderate intensity presented simultaneously with a click diminished the size of the click-evoked response.

Pure-tone auditory threshold in school children

2011 ◽  
Vol 269 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Reinhard Müller ◽  
Gerald Fleischer ◽  
Joachim Schneider
Keyword(s):  
School Children ◽  
Pure Tone ◽  
Auditory Threshold

Delayed loss of residual hearing in Clarion® cochlear implant users

2003 ◽  
Vol 117 (11) ◽  
pp. 850-853 ◽  
Author(s):  
M. Barbara ◽  
A. Mattioni ◽  
S. Monini ◽  
I. Chiappini ◽  
F. Ronchetti ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Cochlear Implantation ◽  
Pure Tone ◽  
Hearing Threshold ◽  
Auditory Threshold ◽  
Residual Hearing ◽  
Equal Distribution ◽  
Hearing Thresholds ◽  
Number Of Patients ◽  
Over Time

Hearing threshold has been measured in a group of patients following cochlear implantation with a Clarion® device for the last eight years. The patients had received either a pre-curved carrier or the Hi-Focus I plus Electrode Positioner System (EPS). The assessment was carried out within the first post-operative week as well as at a later stage, between six and 87 months, post-operatively. Residual hearing thresholds were still measurable early after surgery in 24.5 per cent of the patients, without differences between the two different Clarion® models. However, the number of subjects with measurable hearing dropped to 16.3 per cent as observed when hearing was measured at a later stage, with an equal distribution between the two groups of patients. From this study it has been possible to observe that only a limited number of patients maintain residual hearing after Clarion® cochlear implantation, and that this tends to decrease further over time. Nevertheless, the performance of these patients for speech tests did not appear to be affected by deterioration of the pure-tone auditory threshold.

Auditory Perceptual Thresholds in Brain-Injured Children

1965 ◽  
Vol 8 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Howard A. Grey ◽  
Michael J. D’Asaro ◽  
Maurice Sklar
Keyword(s):  
Hearing Loss ◽  
Brain Injury ◽  
Young Children ◽  
White Noise ◽  
Hearing Impairment ◽  
Pure Tone ◽  
Diagnostic Categories ◽  
Brain Injured

This study investigated the effects of congenital brain injury alone, or in combination with sensori-neural hearing loss, upon figure-ground thresholds for spondees in young children. Forty-eight subjects were selected from four diagnostic categories: (1) brain injured, normally hearing; (2) brain-injured, hearing-handicapped, (3) non-brain-injured, normally hearing; and (4) non-brain-injured, hearing-handicapped. Brain-injured and non-brain-injured subjects were matched for pure-tone thresholds. Selected spondees were presented bilaterally, first in quiet then in a background of white noise. Results indicated no effect upon speech thresholds by brain injury, and no apparent interaction between brain injury and hearing impairment.

Effect of contralateral pure tone stimulation on distortion emissions suggests a frequency-specific functioning of the efferent cochlear control

2012 ◽  
Vol 107 (7) ◽  
pp. 1962-1969 ◽  
Author(s):  
H. Althen ◽  
A. Wittekindt ◽  
B. Gaese ◽  
M. Kössl ◽  
C. Abel
Keyword(s):  
White Noise ◽  
Otoacoustic Emissions ◽  
Pure Tone ◽  
Specific Effect ◽  
Outer Hair Cells ◽  
Efferent Activity ◽  
Distortion Product ◽  
Frequency Specificity ◽  
Olivocochlear System ◽  
Pure Tones

Contralateral acoustic stimulation (CAS) with white noise and pure tone stimuli was used to assess frequency specificity of efferent olivocochlear control of cochlear mechanics in the gerbil. Changes of the cochlear amplifier can be monitored by distortion product otoacoustic emissions (DPOAEs), which are a byproduct of the nonlinear amplification by the outer hair cells. We used the quadratic DPOAE f2-f1 as ipsilateral probe, as it is known to be sensitive to efferent olivocochlear activity. White noise CAS, used to evoke efferent activity, had maximal effects on the DPOAE level for f2-stimulus frequencies of 5–7 kHz. The dominant effect during CAS was a DPOAE level increase of up to 13.5 dB. The frequency specificity of the olivocochlear system was evaluated by presenting pure tones (0.5–38 kHz) as contralateral stimuli to evoke efferent activity. Maximal DPOAE level changes were triggered by CAS frequencies close to the frequency of the DPOAE elicitor tones (tested f2 range: 2.5–15 kHz). The effective CAS frequency range covered 1.4–2.4 octaves and was centered 0.42 octaves below the DPOAE elicitor tone f2. The frequency-specific effect of CAS with pure tones suggests a dedicated central control of mechanical adjustments for peripheral frequency processing.

The Change-Deafness Phenomenon in Harmonic Chords

2014 ◽  
Vol 73 (3) ◽  
pp. 143-152 ◽  
Author(s):  
Robert Schnuerch ◽  
Carina Kreitz ◽  
Martin Heil ◽  
Kathrin Lange
Keyword(s):  
White Noise ◽  
Pure Tone ◽  
Poor Performance ◽  
Time Dependent ◽  
Fundamental Aspect ◽  
Present Evidence ◽  
Auditory Enhancement ◽  
Auditory Experience ◽  
Change Deafness ◽  
Auditory Scenes

Previous research has demonstrated surprisingly poor performance in participants who are asked to detect changes in briefly disrupted auditory scenes. So far, this change-deafness phenomenon has been found in naturalistic sound scenes and random pure-tone stacks. We now present evidence for this effect in harmonic chords, that is, in a different, yet fundamental aspect of human auditory experience. We investigated the influence of the type of disruption and its duration on change detection. Change deafness was observed regardless of whether white noise or silence had disrupted the chords and was stronger for deleted than for added tones. Crucially, the change-deafness effect was only observed for gaps exceeding 60 ms, and increased with gap durations up to 2000 ms. The present data, in line with previous studies using different stimuli, support the view that the effect is due to a masking of the change-related transient and to the decay of a time-dependent process. For the stimuli at hand, the decay of neural-adaptation-based auditory enhancement is suggested.

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