Hearing in the ferret (Mustela putorius): Thresholds for pure 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.

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Decision Criteria for Pure-Tone Detection Used by Two Age Groups of Normal-Hearing and Hearing-Impaired Listeners

Journal of Gerontology ◽

10.1093/geronj/46.2.p67 ◽

1991 ◽

Vol 46 (2) ◽

pp. P67-P70 ◽

Cited By ~ 7

Author(s):

L. Marshall

Keyword(s):

Pure Tone ◽

Age Groups ◽

Normal Hearing ◽

Hearing Impaired ◽

Decision Criteria ◽

Two Age Groups ◽

Tone Detection

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Research of Pure Tone Detection for Faulted On-Vehicle Loudspeakers Based on Image Fractal

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.494-495.171 ◽

2014 ◽

Vol 494-495 ◽

pp. 171-174 ◽

Cited By ~ 1

Author(s):

Gui Ling Tan ◽

Yu Ming Qi ◽

San Peng Deng ◽

De Hua Miao ◽

Wen Hua Gao

Keyword(s):

Pure Tone ◽

Wavelet Packet ◽

Detection Accuracy ◽

Monitoring Method ◽

Time Frequency ◽

Two Dimensional Image ◽

Box Counting ◽

Fault Recognition ◽

Box Counting Dimension ◽

Tone Detection

At present, the detection accuracy of monitoring method by human ears is not satisfying in the pure tone detection of on-vehicle loudspeakers. To solve this problem, a new method is proposed to convert vehicle loudspeakers response signals into a two-dimensional image signal via wavelet packet analysis, which can increase the time-frequency of malfunction information. Through image binaryzation and pretreatment image-edge detection, the resulting signal would be recognized with box-counting dimension acquired in the process of gaining time-frequency image through fractal dimension as malfunctioned indications. Experiments show a rate of fault recognition as high as 95% , which meet the requirements of online vehicle loudspeaker detection.

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Hearing in the ferret (Mustela putorius): effects of primary auditory cortical lesions on thresholds for pure tone detection

Journal of Neurophysiology ◽

10.1152/jn.1988.60.3.879 ◽

1988 ◽

Vol 60 (3) ◽

pp. 879-888 ◽

Cited By ~ 15

Author(s):

G. L. Kavanagh ◽

J. B. Kelly

Keyword(s):

Hearing Loss ◽

Pure Tone ◽

Primary Auditory Cortex ◽

Complete Recovery ◽

Frequency Range ◽

Repeated Testing ◽

Mustela Putorius ◽

Before And After ◽

Very High Frequencies

1. Pure tone thresholds were determined for five adult male ferrets before and after bilateral ablation of primary auditory cortex. Complete audiograms ranging from 0.016 to 48 kHz were obtained for two animals. The remaining three animals were tested at five frequencies selected to assess hearing throughout the audible range (0.125, 0.5, 2.0, 8.0, and 32.0 kHz). 2. Shortly after surgery one animal had elevated thresholds across the entire frequency range with the most pronounced hearing loss above 12.0 kHz. Four other animals had no elevation of thresholds at low and midrange frequencies but suffered a hearing loss at very high frequencies (32 kHz). 3. Repeated testing over a period of several months revealed substantial recovery of sensitivity. There was complete recovery of sensitivity in the low- and middle-frequency range of the audiogram. Some hearing loss persisted at the extreme upper end of the audiogram (32 kHz), but in two cases there was evidence of recovery at this frequency as well. 4. Following determination of absolute thresholds all animals were assessed for their ability to localize sound in space. Minimum audible angles were obtained on midline as well as within both left and right hemifields, i.e., around 0, -60 and +60 degrees azimuth. All animals had severe and persistent deficits in their ability to localize brief sounds within the lateral fields, but were still capable of midline localization.

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