Growth and recovery of temporary threshold shift at 3 kHz in bottlenose dolphins: Experimental data and mathematical models

2010 ◽  
Vol 127 (5) ◽  
pp. 3256-3266 ◽  
Author(s):  
James J. Finneran ◽  
Donald A. Carder ◽  
Carolyn E. Schlundt ◽  
Randall L. Dear
Keyword(s):  
Experimental Data ◽  
Mathematical Models ◽  
Bottlenose Dolphins ◽  
Threshold Shift ◽  
Temporary Threshold Shift

scholarly journals Temporary threshold shift in bottlenose dolphins (Tursiops truncatus) exposed to mid-frequency tones

2005 ◽  
Vol 118 (4) ◽  
pp. 2696-2705 ◽  
Author(s):  
James J. Finneran ◽  
Donald A. Carder ◽  
Carolyn E. Schlundt ◽  
Sam H. Ridgway
Keyword(s):  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
Threshold Shift ◽  
Temporary Threshold Shift

Theoretical approach to estimating the induction of hearing impairment in bottlenose dolphins by radiated leisure boat noise

2011 ◽  
Vol 92 (8) ◽  
pp. 1887-1892 ◽  
Author(s):  
Jonathan A. David
Keyword(s):  
Hearing Impairment ◽  
Coastal Waters ◽  
Sound Pressure ◽  
Bottlenose Dolphins ◽  
Pressure Level ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Underwater Noise ◽  
Noise Levels ◽  
Close Range

Coastal waters are being subjected to underwater noise generated by increasing numbers of leisure and tour boats. Such noise has the potential to impair the hearing of neighbouring bottlenose dolphins, particularly as the noise from several distributed boats could summate at the point of reception. This potential has been assessed by comparing small boat noise, recorded over a range of 8–532 m, with noise that is known to induce hearing impairment in the form of a temporary threshold shift (TTS) or permanent threshold shift (PTS). Extrapolation of broadband boat noise levels yielded a minimum source sound pressure level of 156 dB re 1μPa at 1 m. An equal-energy model for TTS-onset predicted that boat noise could induce a TTS after 1 hour's exposure at 1.3 m and after 8 hours' exposure at 2.3 m. These distances increased with additional adjacent boats. Leisure boats are unlikely to induce a PTS, even at close range.

Decay of Temporary Threshold Shift in Noise

1973 ◽  
Vol 16 (2) ◽  
pp. 267-270 ◽  
Author(s):  
John H. Mills ◽  
Seija A. Talo ◽  
Gloria S. Gordon
Keyword(s):  
Sound Field ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Octave Band ◽  
Band Noise ◽  
Lower Asymptote

Groups of monaural chinchillas trained in behavioral audiometry were exposed in a diffuse sound field to an octave-band noise centered at 4.0 k Hz. The growth of temporary threshold shift (TTS) at 5.7 k Hz from zero to an asymptote (TTS ∞ ) required about 24 hours, and the growth of TTS at 5.7 k Hz from an asymptote to a higher asymptote, about 12–24 hours. TTS ∞ can be described by the equation TTS ∞ = 1.6(SPL-A) where A = 47. These results are consistent with those previously reported in this journal by Carder and Miller and Mills and Talo. Whereas the decay of TTS ∞ to zero required about three days, the decay of TTS ∞ to a lower TTS ∞ required about three to seven days. The decay of TTS ∞ in noise, therefore, appears to require slightly more time than the decay of TTS ∞ in the quiet. However, for a given level of noise, the magnitude of TTS ∞ is the same regardless of whether the TTS asymptote is approached from zero, from a lower asymptote, or from a higher asymptote.

Damage Risk: An Evaluation of the Effects of Exposure to 85 versus 90 dBA of Noise

1976 ◽  
Vol 19 (2) ◽  
pp. 216-224 ◽  
Author(s):  
James T. Yates ◽  
Jerry D. Ramsey ◽  
Jay W. Holland
Keyword(s):  
White Noise ◽  
Statistical Difference ◽  
Noise Exposure ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Noise Levels ◽  
Potential Damage ◽  
Full Day ◽  
Damage Risk

The purpose of this study was to compare the damage risk of 85 and 90 dBA of white noise for equivalent full-day exposures. The damage risk of the two noise levels was determined by comparing the temporary threshold shift (TTS) of 12 subjects exposed to either 85 or 90 dBA of white noise for equivalent half- and full-day exposures. TTS was determined by comparing the pre- and postexposure binaural audiograms of each subject at 1, 2, 3, 4, 6, and 8 kHz. It was concluded that the potential damage risk, that is, hazardous effect, of 90 dBA is greater than 85 dBA of noise for equivalent full-day exposures. The statistical difference between the overall effects of equivalent exposures to 85 dBA as compared to 90 dBA of noise could not be traced to any one frequency. The damage risk of a full-day exposure to 85 dBA is equivalent to that of a half-day exposure to 90 dBA of noise. Within the limits of this study, TTS t was as effective as TTS 2 for estimating the damage risk of noise exposure.

Acoustic-Reflex Dynamics for Pulsed Signals

1978 ◽  
Vol 21 (2) ◽  
pp. 295-308
Author(s):  
Terry L. Wiley ◽  
Raymond S. Karlovich
Keyword(s):  
Duty Cycle ◽  
Acoustic Impedance ◽  
Normal Hearing ◽  
Broadband Noise ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Acoustic Reflex ◽  
Stapedius Muscle ◽  
Duty Cycles

Contralateral acoustic-reflex measurements were taken for 10 normal-hearing subjects using a pulsed broadband noise as the reflex-activating signal. Acoustic impedance was measured at selected times during the on (response maximum) and off (response minimum) portions of the pulsed activator over a 2-min interval as a function of activator period and duty cycle. Major findings were that response maxima increased as a function of time for longer duty cycles and that response minima increased as a function of time for all duty cycles. It is hypothesized that these findings are attributable to the recovery characteristics of the stapedius muscle. An explanation of portions of the results from previous temporary threshold shift experiments on the basis of acoustic-reflex dynamics is proposed.

On the Potential Deterioration in Hearing Due to Hearing Aid Usage

1981 ◽  
Vol 24 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Larry E. Humes ◽  
Fred H. Bess
Keyword(s):  
Hearing Aid ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Hearing Sensitivity

This manuscript examines the issue of potential decline in hearing sensitivity due to hearing aid usage through an analysis of data obtained from the temporary threshold shift (TTS) paradigm. Following a critique of the traditional measures of TTS, the concept of integrated TTS (ITTS) is reviewed and data on hearing-aid-induced ITTS are presented. In addition, a series of equations relating permanent threshold shift (PTS) to a recently developed measure of noise dose (Dn) is derived and predictions for hearing-aid-induced PTS are made. Recommended gain settings established to protect the hearing of a person wearing a hearing aid from further decline following various durations of hearing aid usage are also provided.

Integrating experimental data and mathematical models in simulation of physical systems

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1787-1790
Author(s):  
Boris A. Zeldin ◽  
Andrew J. Meade
Keyword(s):  
Experimental Data ◽  
Mathematical Models ◽  
Physical Systems
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