scholarly journals A pure‐tone‐induced temporary threshold shift on normal hearing and noise‐induced permanent threshold shift

1987 ◽  
Vol 82 (S1) ◽  
pp. S26-S26
Author(s):  
I. M. Young ◽  
L. D. Lowry
1978 ◽  
Vol 21 (2) ◽  
pp. 295-308
Author(s):  
Terry L. Wiley ◽  
Raymond S. Karlovich

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.


1974 ◽  
Vol 17 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Raymond S. Karlovich ◽  
Terry L. Wiley

The test ear of each of nine normal-hearing subjects was exposed for three minutes to a 1000-Hz tone at 110 dB SPL. Either a 4000-Hz tone at 105 dB SPL or a broad-band noise at 100 dB SPL was presented to the contralateral ear during exposure. Four different temporal patterns were used for each contralateral signal: (1) continuous, (2) 18 seconds on/18 seconds off, (3) 1.8 seconds on/1.8 seconds off, and (4) 0.18 seconds on/0.18 seconds off. A control condition, consisting of the absence of contralateral stimulation, also was used. Pre- and postexposure thresholds for the test ear were tracked at a signal one-half octave above the exposure frequency. Resultant data indicated that reduction in temporary threshold shift was greatest for conditions involving rapidly pulsed (1.8 and 0.18 seconds on-off) contralateral signals. We hypothesized that these data were reflective of the dynamic properties of the acoustic reflex. Specifically, we posited that the acoustic reflex manifests less adaptation in response to rapid signal-repetition rates and relatively more adaptation to sustained or slowly pulsed signals.


1994 ◽  
Vol 37 (6) ◽  
pp. 1450-1458 ◽  
Author(s):  
John H. Macrae

This study used a well-verified mathematical model to predict asymptotic temporary threshold shift (ATS) caused by hearing aid use. The model determined the amounts of ATS to be expected if real ear insertion gains (REIGs) recommended by the current National Acoustic Laboratories (NAL) procedure are used. It also determined the consequences of use of excess REIG and of high input levels to hearing aids. If recommended REIGs are used and input levels are normal (average A-weighted input levels of about 61 dB SPL), ATS is unlikely to occur for clients who have typical audiograms with three-frequency average pure-tone thresholds (PTAs) less than 60 dB HL. For people with PTAs greater than 60 dB HL, small amounts of ATS can be expected to occur during hearing aid use, but these amounts of ATS are safe, that is, unlikely to be associated with permanent threshold shift (PTS) for individuals with all PTAs except those greater than about 100 dB HL. If REIGs are 15 dB greater than those recommended, the amounts of ATS will be unsafe for people with PTAs greater than about 80 dB HL. It appears unwise for clients who have this degree of hearing loss to use excess REIG. The use of excess REIG in high ambient levels of sound (average A-weighted input levels of about 75 dB SPL) is likely to cause PTS for hearing aid users with PTAs of about 50 dB HL or greater. Clients who prefer to use excess REIG should therefore avoid high ambient sound levels. The amount of amplification required for people with PTAs greater than about 100 dB HL is likely to cause PTS and is therefore inherently unsafe.


2012 ◽  
Vol 33 (6) ◽  
pp. e44-e58 ◽  
Author(s):  
Colleen G. Le Prell ◽  
Shawna Dell ◽  
Brittany Hensley ◽  
James W. Hall ◽  
Kathleen C. M. Campbell ◽  
...  

2017 ◽  
Vol 141 (5) ◽  
pp. 3814-3814 ◽  
Author(s):  
Anthony J. Brammer ◽  
Gongqiang Yu ◽  
James J. Grady ◽  
Kourosh Parham ◽  
Martin G. Cherniack ◽  
...  

Author(s):  
Nuriye Yıldırım Gökay ◽  
Bülent Gündüz ◽  
Fatih Söke ◽  
Recep Karamert

Purpose The effects of neurological diseases on the auditory system have been a notable issue for investigators because the auditory pathway is closely associated with neural systems. The purposes of this study are to evaluate the efferent auditory system function and hearing quality in Parkinson's disease (PD) and to compare the findings with age-matched individuals without PD to present a perspective on aging. Method The study included 35 individuals with PD (mean age of 48.50 ± 8.00 years) and 35 normal-hearing peers (mean age of 49 ± 10 years). The following tests were administered for all participants: the first section of the Speech, Spatial and Qualities of Hearing Scale; pure-tone audiometry, speech audiometry, tympanometry, and acoustic reflexes; and distortion product otoacoustic emissions (DPOAEs) and contralateral suppression of DPOAEs. SPSS Version 25 was used for statistical analyses, and values of p < .05 were considered statistically significant. Results There were no statistically significant differences in the pure-tone audiometry thresholds and DPOAE responses between the individuals with PD and their normal-hearing peers ( p = .732). However, statistically significant differences were found between the groups in suppression levels of DPOAEs and hearing quality ( p < .05). In addition, a statistically significant and positive correlation was found between the amount of suppression at some frequencies and the Speech, Spatial and Qualities of Hearing Scale scores. Conclusions This study indicates that medial olivocochlear efferent system function and the hearing quality of individuals with PD were affected adversely due to the results of PD pathophysiology on the hearing system. For optimal intervention and follow-up, tasks related to hearing quality in daily life can also be added to therapies for PD.


1973 ◽  
Vol 16 (2) ◽  
pp. 267-270 ◽  
Author(s):  
John H. Mills ◽  
Seija A. Talo ◽  
Gloria S. Gordon

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.


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