Suppressibility of the 2f1-f2 stimulated acoustic emissions in gerbil and man.
The suppression tuning properties of the oto-acoustic distortion product emission, 2f1-f2 have been measured in the ear canal of gerbil and man. The results show the acoustic response to be suppressible in a similar, frequency-dependent manner in both species. Frequencies near to those of the stimulating tones are most effective in suppressing the response. Derived iso-suppression tuning curves have Q10dB values of between 1 and 6. Suppressor tones having frequencies near to f2 (the higher frequency stimulus) make a contribution to the tuning curve which is largely independent of the stimulus intensity and the frequency ratio between the two primary tones. Suppressors having f1-associated frequencies produce a variable amount of suppression depending on the stimulus parameters chosen. No specific suppression feature could be associated with suppressors near to 2f1-f2. The frequency selectivity of the acoustic DP generation mechanism shown by this study indicates a close association with the transduction mechanism. The demonstration of comparable signals in gerbil and man facilitates the direct transfer of laboratory results to the study of human ears.
D000161:Acoustic Stimulation; D000818:Animals; D003051:Cochlea / Q000502:physiology; D004424:Ear Canal / Q000502:physiology*; D005849:Gerbillinae; D006309:Hearing / Q000502:physiology; D006801:Humans; D012022:Reflex, Acoustic