Studies in electroencephalographic audiometry

Gatehouse, Stuart (1977) Studies in electroencephalographic audiometry. PhD thesis, University of Glasgow.

Abstract

This thesis investigates the application of steady state responses to averaged electroencephalographic audiometry (AEA). Steady state responses may be obtained using either amplitude modulated or frequency modulated stimulation. In both cases the stimulus variables are modulation frequency, modulation depth, carrier frequency and stimulus intensity. Other variables include the number of samples used to compile the average, the stimulus presentation (i.e. monaural or binaural), and the subject state (e.g. awake or under sedation). The effect of these parameters on the responses to both amplitude and frequency modulated stimulation has been investigated for normal hearing adults and children. For amplitude modulated stimulation the effect of modulation frequency exhibits a large degree of inter-subject variability, while the response behaviour as a function of the other parameters does not;. The optimal conditions for audiological assessment have been determined for all parameters with the exception of modulation frequency, which is a function of the individual. For frequency modulated stimulation, the inter-subject variability is small, and optimal conditions have been determined for all parameters. The steady state response thresholds to both amplitude and frequency modulated stimulation have been determined for adult and child clinical subjects. These thresholds were compared with the behavioural thresholds obtained using conventional audiometry. The responses to amplitude modulated stimulation may be obtained at 20 dB above behavioural threshold, and those to frequency modulated stimulation at 40 dB above behavioural threshold. Some of the relationships between the two forms of steady state response, the transient response, and the electroencephalogram have been investigated, and the advantages and disadvantages of the steady state responses as an audiological technique have been discussed.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: J A Simpson
• Keywords: Neurosciences, Audiology
• Date of Award: 1977
• Depositing User: Enlighten Team
• Unique ID: glathesis:1977-72087
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 24 May 2019 15:11
• Last Modified: 24 May 2019 15:11
• URI: https://theses.gla.ac.uk/id/eprint/72087