Mean behavioral threshold (dB SPL) as a function of f 2 frequency (kHz). Error bars represent ±1 SD. Data from 9 to 19 HI subjects were used to derive these values, although the same subjects are not represented at each frequency for a given hearing-loss category. NH thresholds, based on data from 19 to 20 subjects, are plotted for comparison purposes (Gorga et al., 2011a).
Mean level (dB SPL) ±1 SD as a function of L 2 (dB SL). Open circles represent mean DPOAE level (Ld ) and filled triangles represent mean noise levels. Data from NH (Gorga et al., 2011a) and the three HI groups are plotted. These data represent mean levels measured during control conditions in which no suppressor was present.
Mean DPOAE decrement (dB) as a function of suppressor level (L 3, dB SPL). Data for the on-frequency suppressor condition is plotted for each subject group at each of four f 2 frequencies. The level of the probe (L 2) was set at 20 dB SL. Open circles represent the mean difference in Ld between control conditions and the conditions in which a suppressor was present (decrements). Error bars represent ±1 SD. Filled circles represent the transformed decrements which were fit with a simple linear regression, shown as a line within each panel. The vertical dashed lines represent “suppression threshold” (decrement of 3 dB). These best fit lines and suppression thresholds provided the estimate of slope, provided as an inset in each panel, and were used in the construction of functions relating suppression threshold to L 2 (Fig. 6) and in the construction of STCs (Gruhlke et al., 2012).
(Color online) Mean slope of the decrement function as a function of f 3 in octaves relative to f 2. Data for each subject group is represented in each panel, as indicated by the inset in the upper left panel. Data for a different L 2 (dB SL) are shown in each row and data for a different f 2 are shown in each column.
(Color online) Same as Fig.4, only here L 2 is represented in dB SPL.
(Color online) Mean L 3 for 3 dB of suppression as a function of L 2. Data for each of the subject groups is shown within each panel, as indicated by the inset in the upper left panel. (a) Data when L 2 is set in dB SL; (b) data when L 2 is set in dB SPL. The top row in each set of eight panels shows data for the low-frequency suppressor condition (f 3 = f 2 − 1 octave), and the bottom row in each set of eight panels shows data for the on-frequency suppressor conditions (f 3 ≈ f 2).
Number of subjects included at each f 2 in each of four subject groups.
L 1, L 2 (dB SPL) combinations used to elicit a DPOAE for each of the four f 2 frequencies.
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