Susceptance and conductance changes in acoustic reflexometry.

: Acoustic reflexometry was performed on 30 otologically and audiologically normal subjects. An otoadmittance meter was used as the reflex indicator. The magnitude and direction of susceptance and conductance changes were recorded for the acoustic reflex at 220- and 660-Hz probe (carrier) tones. Susceptance and conductance changed in a negative direction (decreased) in 100% of the reflex responses when the probe tone was 220 Hz. With 660-Hz probe tones, susceptance changed positively (increased) and conductance negatively in about 90% of all the reflexes. There was an inverse relationship between probe frequency and magnitude of admittance change during reflex. A direct relationship was found for the amount of input admittance phase shift and probe frequency.