The post-auricular muscle reflex (PAMR): Its detection, analysis, and use as an objective hearing test
Degree GrantorUniversity of Western Australia
Degree NameBachelor of Science (Hons)
A number of fundamental characteristics of the post-auricular muscle response (PAMR) have been examined in adult and infant human subjects using an automated computer-based measurement system. This system allowed simultaneous examination of the changes in background electrical activity of the PAM, and extraction of information regarding the sound-evoked PAMR waveform, such as response amplitude and peak latency. It was found that the PAMR was best recorded using an active electrode located directly over the body of the muscle, and a reference electrode located on the dorsal surface of the pinna. In addition, it was found that during lateral rotation of the eyes towards the recording electrodes the peak-to-peak amplitude of the PAMR increased by an average of 525%. The increase in response amplitude was highly correlated with the increase in EMG observed during this manoeuvre, suggesting that the mechanisms that increase both EMG and PAMR amplitude probably occur at a common point. The voltage spectrum of the PAMR was also measured. Contrary to previous findings (Thornton, 1975), the voltage spectrum of the PAMR extended from 10 Hz to approximately 550 Hz, with a broad spectral peak centred between 70 Hz and 115 Hz. Finally, a cheap, efficient and reliable objective hearing test was developed, using the correlation measure of the PAMR. The availability of such a device has the potential to vastly increase the number of children that are screened for hearing disorders, especially in poorer communities who do not have the funds or the expertise to establish screening programs using the currently available objective techniques of ABR and oto-acoustic emission measurement.
SubjectsField of Research::11 - Medical and Health Sciences::1116 - Medical Physiology
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