Speech intelligibility in stapedectomized individuals.

We assessed the types of speech errors made in relation to the acoustic reflex. Ten subjects with unilateral stapedectomies were presented with consonant-vowel nonsense syllables in low pass noise at 70, 95, and 110 dB SPL in each ear. Hearing sensitivity for all subjects was normal or near-normal bilaterally. In the operated ear, speech intelligibility was significantly poorer than in the unoperated ear at all intensity levels. A distinctive feature analysis supported this finding. The data suggest that word discrimination testing in quiet does not adequately reveal the success of stapedectomy surgery. The distinctive feature analysis indicated that rather than consider the acoustic reflex as limiting the forward spread of masking into high frequencies, it would be better to describe it as a general aural overload regulator.