The general swept-tone SFOAE procedure is detailed in a previous report
(Mishra & Talmadge 2018 (link)). SFOAE
measurements were performed using an ER-10B+ probe microphone system with ER-2
transducers (Etymotic Research, Elk Grove Village, IL). Stimulus calibration in
the ear canal was performed using a depth-compensated technique (Lee et al. 2012 (link); Mishra & Abdala 2015 ). Probe and suppressor tones, at 40 and 60
dB SPL respectively, were swept at a rate of 0.188 octaves/s in a two-interval
paradigm. The suppressor frequency was 1.1 times higher than the probe
frequency. The sweeps consisting probe only, and both probe and suppressor tones
were interleaved, and the phase was inverted for every other use of the
suppressor. SFOAEs were estimated from at least 8 probe and
probe-plus-suppressor pairs using a least-squares fit method. The least-squares
fit models both probe and suppressor sweeps and estimates SFOAEs to minimize the
sum of the squared error between the model and the response. The noise floor is
estimated from the average of pairwise sweep difference obtained by subtracting
the probe from the probe-plus-suppressor.
(Mishra & Talmadge 2018 (link)). SFOAE
measurements were performed using an ER-10B+ probe microphone system with ER-2
transducers (Etymotic Research, Elk Grove Village, IL). Stimulus calibration in
the ear canal was performed using a depth-compensated technique (Lee et al. 2012 (link); Mishra & Abdala 2015 ). Probe and suppressor tones, at 40 and 60
dB SPL respectively, were swept at a rate of 0.188 octaves/s in a two-interval
paradigm. The suppressor frequency was 1.1 times higher than the probe
frequency. The sweeps consisting probe only, and both probe and suppressor tones
were interleaved, and the phase was inverted for every other use of the
suppressor. SFOAEs were estimated from at least 8 probe and
probe-plus-suppressor pairs using a least-squares fit method. The least-squares
fit models both probe and suppressor sweeps and estimates SFOAEs to minimize the
sum of the squared error between the model and the response. The noise floor is
estimated from the average of pairwise sweep difference obtained by subtracting
the probe from the probe-plus-suppressor.
