by Oliver » Mon Jun 11, 2012 9:00 am
Dear Masud,
The stimulus rate for TEOAE is dependent on the length of the response window that is required. Unlike Auditory Brainstem Responses the stimulus rate does not significantly alter the response recorded within the response window, so the stimulation rate is set to the maximum possible for the response window set.
The response window is set on V6 in Options->Stims->Stim type. The 'Linear' and 'Non linear' settings have response window of 20.48ms - giving a stimulus rate of 48.8Hz. The 'Quickscreen' setting has a response window of 12.8ms giving a stimulus rate of 78.1Hz.
Low frequency TEOAEs are recorded later in the response window than high frequency OAEs, so the 'Quickscreen' 12.8ms window will reduce the amplitude of low frequency emissions recorded, but will collect data faster.
You describe the presentation rate as 'slow' this may be due to the way the NLo figure is calculated; the figure on V6 'NLo' represents sets of 8 (for 'Non Linear') or 16 (for 'Quickscreen') stimuli presented, not individual stimuli.
I hope this answers your questions,
Yours,
Oliver Brill
Product Scientist
Otodynamics