Research Article

Effect of sound conditioning on click auditory brainstem response threshold shifts in guinea pigs


Background and Aim: Sound conditioning is exposure to a non-traumatic, moderate level of sound which increases inner ear resistance against further severe noise. In this study, we aimed to survey the effect of sound conditioning on auditory brainstem response (ABR) threshold shifts using click stimulus, and the effect of the frequency of conditioning on hearing protection.
Methods: Fifteen guinea pigs were randomly divided into 3 groups. Two conditioned groups were exposed to 1 kHz, and 4 kHz octave band noise at 85 dB SPL, 6 hours per day for 5 days, respectively. On the sixth day, the animals were exposed to 4 kHz octave band noise at 105 dB SPL, for 4 hours. The control group was exposed to intense noise, 4 kHz at 105 Db SPL for 4 hours (without conditioning). After exposure, ABR thresholds using click were recorded an hour, and 7 days after noise exposure.
Results: The results of the ABR with click stimulus showed less thresold shifts in conditioned groups than control (p≤0.001). Comparison of the results of conditioned groups, showed less threshold shift by 4 kHz conditioning, however, this difference was not statistically significant (p>0.05).
Conclusion: Electrophysiological data of our study showed that sound conditioning has a protective effect against subsequent intensive noise exposure, and the frequency of conditioning does not have significant effect on ABR threshold shifts when using click stimulus.

1. Duan M, Qiu J, Laurell G, Olofsson A, Counter SA, Borg E. Dose and time-dependent protection of the antioxidant N-L-acetylcysteine against impulse noise trauma. Hear Res. 2004;192(1-2):1-9.
2. Hu BH, Henderson D, Nicotera TM. Involvement of apoptosis in progression of cochlear lesion following exposure to intense noise. Hear Res. 2002;166(1-2):62-71.
3. Niu X, Canlon B. Protecting against noise truma by sound conditioning. J Sound Vib. 2002:250(1);115-8.
4. Harris KC, Bielefeld E, Hu BH, Henderson D. Increased resistance to free radical damage induced by low-level sound conditioning. Hear Res. 2006;213(1-2):118-29.
5. Zuo H, Cui B, She X, Wu M. Changes in Guinea pig cochlear hair cells after sound conditioning and noise exposure. J Occup Health. 2008;50(5):373-9.
6. Yamasoba T, Dolan DF, Miller JM. Acquired resistance to acoustic trauma by sound conditioning is primarily mediated by changes restricted to the cochlea, not by systemic responses. Hear Res. 1999;127(1-2):31-40.
7. Niu X, Canlon B. Protective mechanisms of sound conditioning. Adv Otorhinolaryngol. 2002;59:96-105.
8. Canlon B, Borg E, Flock A. Protection against noise trauma by pre-exposure to a low level acoustic stimulus. Hear Res. 1988;34(2):197-200.
9. Canlon B, Fransson A. Morphological and functional preservation of the outer hair cells from noise trauma by sound conditioning. Hear Res. 1995;84(1-2):112-24.
10. Yoshida N, Liberman MC. Sound conditioning reduces noise-induced permanent threshold shift in mice. Hear Res. 2000;148(1-2):213-9.
11. Wang Y, Liberman MC. Restraint stress and protection from acoustic injury in mice. Hear Res. 2002;165(1-2):96-102.
12. Canlon B, Fransson A. Reducing noise damage by using a mid-frequency sound conditioning stimulus. Neuroreport. 1998;9(2):269-74.
13. Subramaniam M, Henderson D, Campo P, Spongr V. The effect of 'conditioning' on hearing loss from a high frequency traumatic exposure. Hear Res. 1992;58(1):57-62.
14. Ahroon WA, Hamernik RP. Noise-induced hearing loss in the noise-toughened auditory system. Hear Res. 1999;129(1-2):101-10.
IssueVol 21 No 3 (2012) QRcode
SectionResearch Article(s)
Sound conditioning hearing protection noise-induced hearing loss guinea pigs

Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
How to Cite
Imani A, Pourbakht A, Akbari M, Motalebi Kashani M. Effect of sound conditioning on click auditory brainstem response threshold shifts in guinea pigs. Aud Vestib Res. 2017;21(3):77-85.