The normal middle ear reflex thresholds towards white noise and acoustic clicks in young adults

The acoustic middle ear muscle reflex thresholds towards white noise and fast sequences of clicks were determined in 46 normal-hearing young adults using electronic averaging. For white noise the thresholds were normally distributed around an average value of 72.7 dB SPL. With sequences of clicks the threshold depended above all on the click repetition rate within each stimulus sequence. When the repetition was 128/sec the threshold distribution was almost normal around an average value of 73.9 dB SPL. For the individual test subject there was good correlation between the white noise and the click reflex thresholds. It was our impression that the click generated reflexes had a more well defined threshold than with white noise stimuli, but this impression needs further validation.