Auditory functions in anaesthesia residents during exposure to operating room noise.

Twenty anaesthesia residents were exposed to a pre-recorded audio cassette of operating room noise. The noise level during exposure was maintained at 77.32 +/- 1 dB (A), which was the calculated average operating room noise in our institute. Two auditory functions i.e., speech reception threshold and speech discrimination were studied before and during exposure to noise in a pre-fixed order. The right and left ears were tested separately. Speech reception threshold showed a mean increase of 23.75 +/- 6.86 dB (A) for the right ear and 26.25 +/- 6.90 dB(A) for the left ear during exposure to noise, suggesting that speech communication may be possible only by raising the voice. Speech discrimination showed a mean percentage decrease of 23.3 +/- 4.82 per cent for the right ear and 23.5 +/- 3.89 per cent for the left ear implying that there can be a steep decrease in the ability to discriminate spoken words.