Auditory Brainstem Responses to Single-Slope StimuliThe Influence of Steepness and Polarity

Abstract

Click polarity has little influence on brainstem potentials. We applied an auditory stimulus similar to a step function generated in a closed acoustic system. The influence of stimulus onset steepness (comprising rise time and intensity) on wave V latency and amplitude was investigated. A remarkable latency prolongation was observed for condensation (C) compared with rarefaction (R), if a sharp bend at the foot of the slope was avoided. The C latency lag was nearly the amount of rise time. The effect can be explained by cochlear travel time. Wave V amplitude for R slopes was significantly enhanced. At high intensity and short rise time, it reached twice the values found with C slopes, or with clicks of either polarity. Although the explanations found are not yet satisfactory, a clinical application in cochlear diagnosis is predictable.

Polarity stimulation effects on brainstem auditory evoked potentials

“…Considering that stimulation of Corti organ structures varies according to the polarity, 3 the recorded electrical activity may have specific features when condensation, rarefaction and alternating polarities are used, as seen in BAEP morphology and latency. 4 , 15 , 16 , 17 , 18 , 19 , 20 , 21 Thus, in analyzing the results it is essential to bear in mind that normal absolute and interpeak latencies may vary according to the stimulus polarity. There is, however, no consensus on this in the literature; one study may show that rarefaction is more sensitive and thus superior in clinical practice, while another study states otherwise.…”

Os efeitos da polaridade do estímulo nos Potenciais Evocados Auditivos de Tronco Encefálico

“…4,[15][16][17][18][19][20][21] Thus, in analyzing the results it is essential to bear in mind that normal absolute and interpeak latencies may vary according to the stimulus polarity. There is, however, no consensus on this in the literature; one study may show that rarefaction is more sensitive and thus superior in clinical practice, while another study states otherwise.…”

Druck-, Sog- und alternierende Klickstimulation bei der BERA-Anwendung

“…Da hierbei relativ breite Impulse (Sinushalbwellen mit einer elektrischen Dauer von 250 ps) mit Nachschwingungen bis über 1 ms zur Anwendung kamen, lassen sich die Ergebnisse mit den vorgenannten Arbeiten nur schwer vergleichen, da die Reizparametereinflüsse [10] nicht berücksichtigt werden können. Mit den umfangreichen systematischen Untersu chungen von Gerullet al [11,12] …”