Brainstem auditory evoked potential with speech stimulus.

Background: Although clinical use of the click stimulus for the evaluation of brainstem auditory function is widespread, and despite the fact that several researchers use such stimulus in studies involving human hearing, little is known about the auditory processing of complex stimuli such as speech.

Aim: To characterize the findings of the Auditory Brainstem Response (ABR) performed with speech stimuli in adults with typical development.

Method: Fifty subjects, 22 males and 28 females, with typical development, were assessed for ABR using both click and speech stimuli.

Results: The latencies and amplitudes of the response components onset (V, A and complex VA), the area and slope that occur before 10 ms were identified and analyzed. These measurements were identified in all of the studied subjects and presented wave latency values (ms) of: V = 7.18 (SD = 1.08), A = 8.66 (SD = 1.13); Complex VA = 1.49 (SD = 0.43). For the wave amplitudes (µV), the values were: V = 0.29 (SD = 0.15), A = -0.3 (SD = 0.18); Complex VA = 0.58 (SD = 0. 25). The area measurements (µV X ms) and slope (µV / ms) were 0.27 (SD = 0.17) and 0.4 (SD = 0.17) respectively.

Conclusion: Based on the gathered data it can be observed that this potential works as a new tool for understanding the encoding of sound at the brainstem level.