FREQUENCY-SPECIFIC AUDIOMETRY USING AUDITORY BRAIN-SYSTEM RECORDING - RESULTS AND OVERVIEW OF METHODS

Results and Overview of Methods: Auditory brain stem responses are widely used in objective assessment of hearing function in both children and adults. Because of the lack of frequency specifity, several attempts were made to optimize responses using tone stimuli. Tone stimuli are characterized by intensity, frequency, and duration. Hence, there are important influences on the waveforms with respect to rise, plateau, and fall time. In addition, noise masking techniques are used to suppress both spectral sidebands of the stimulus acid cochlear response not corresponding to the test frequency, In this paper, results on tone burst stimulation in notched noise masking are presented. Using this technique, reproducible waveforms (Jewett I to V resembling peaks) including a middle latency component could be obtained. Various stimulus characteristics (clicks, tone pips, tone bursts, Gaussian shaped stimuli), masking techniques (high-pass noise, notched noise), spectral characteristics, and time saving strategies are critically discussed.