The influence of sound stimulus parameters on the acoustic reflex waveform.

The transient increase in admittance seen at the beginning of the acoustic reflex response in man was investigated with a view to reaching a better understanding of its possible mechanisms. The sound stimulus intensity, its duration and its off-time were varied to investigate their effects on the morphology of the admittance waveform. The results found suggest that the transient increase may not be due to a temporary partial decoupling of the ossicular chain during the initial stages of stapedial contraction, but rather that it may be caused by a slight improvement in the coupling between the middle ear components.