Reducing noise damage by using a mid-frequency sound conditioning stimulus.
Sound conditioning guinea pigs to a 6.3 kHz tone at 78 dB SPL for either 13 or 24 days provides significant physiological (auditory brain stem responses, ABR; and distortion product otoacoustic emissions, DPOAE) and morphological (cochleograms) protection against a subsequent traumatic exposure (6.3 kHz, 100 dB SPL for 24 h) delivered 2 h after sound conditioning. Threshold shifts (ABR, DPOAE) were significantly reduced and the degree of hair cell loss was minimal. When a 1 week pause was given between the end of the sound conditioning and the traumatic exposure, protection was still observed, but to a lesser degree. These findings demonstrate that mid-frequency sound conditioning protects against noise trauma and that the protective effect is maintained for at least 1 week.
Canlon
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B
Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
Fransson
A
A
D000161:Acoustic Stimulation; D000818:Animals; D001306:Auditory Pathways / Q000503:physiopathology; D003213:Conditioning, Psychological / Q000502:physiology*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D006168:Guinea Pigs; D006198:Hair Cells, Auditory / Q000473:pathology; D006317:Hearing Loss, Noise-Induced / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*