[Synthetic sentence identification (SSI) and contralateral acoustic stapedius reflex]

The study of the relationship of the contralateral acoustic reflex with the auditory skill of closure.

To analyze the identification of a speech signal in the presence of competitive sounds in subjects with absence of contralateral acoustic reflex.

Application of the synthetic sentence identification (SSI) test under the conditions of competitive contralateral message (SSI-CCM), with the signal-to-noise ratio of 0 and -40dB, and ipsilateral competitive message (SSI-ICM), with the signal-to-noise ratio of 0, -10, -15 and -20dB, in 43 young adults (group A = 21 subjects with contralateral acoustic reflex present in all of the investigated frequencies, and group B = 22 subjects with contralateral reflex absent at the frequency of 500Hz, or in all of the investigated frequencies, or still in some of the investigated frequencies necessarily including 500Hz), of both gender, with no hearing, otologic or learning disabilities.

The acoustic reflex threshold was above 100dB NA in 59% of the individuals in group B and in 14% of the individuals in group A. All subjects performed according to the normal pattern suggested in the specialized literature for the SSI test. The performance of group B in the SSI-ICM test was inferior to that of group A for all the signal-to-noise ratios used, although the difference was not statistically significant. Group B, which presented an acoustic reflex threshold higher than 100dB NA or the absence of the acoustic reflex, was also the group that presented the worse performance in the SSI test.

The absence of the contralateral acoustic reflex seems to interfere in the identification of the speech signal in the presence of competitive noises.