1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Differences between psychoacoustic and frequency following response measures of distortion tone level and masking
Rent:
Rent this article for
USD
10.1121/1.4751541
/content/asa/journal/jasa/132/4/10.1121/1.4751541
http://aip.metastore.ingenta.com/content/asa/journal/jasa/132/4/10.1121/1.4751541

Figures

Image of FIG. 1.
FIG. 1.

(Color online) Magnitude spectra of FFRs averaged across six subjects with FFRs for the two polarities added (dashed line) or subtracted (solid line). Panels (a) and (b) show the FFR spectra for a frequency-shifted complex tone, presented at 75 dB SPL, for which harmonics 2+3+4 of a 300-Hz F0 were shifted down by 56 Hz in the absence and presence of a narrowband noise (140–440 Hz, presented at 85 dB SPL), respectively. Panels (c) and (d) are as (a) and (b), but with the harmonics shifted up by 56 Hz and a noise in the range of 160–460 Hz. Panels (e) and (f) show the FFR spectra for a 244-Hz 75-dB SPL pure tone in the absence and presence, respectively, of a narrowband noise (84–404 Hz) presented at 90 dB SPL.

Image of FIG. 2.
FIG. 2.

Top (a): Peak height (in dB) at the QDT frequency in the averaged spectra of the FFR waveforms for the two polarities minus the peak height at the QDT frequency in the spectrum of the addition waveform. Bottom (b): Peak height (in dB) in the FFR at the CDT frequency in the averaged spectra of the FFR waveforms for the two polarities minus the peak height at CDT in the spectrum of the subtraction waveform. The frequency-shifted complex was presented at 75 dB SPL. The 300-Hz wide noise had an rms level of 85 dB SPL, and was centered on 290 and 310 Hz for the downward- and upward-shifted complex tones, respectively.

Image of FIG. 3.
FIG. 3.

Mean peak magnitude at 244 Hz (and corresponding standard error) in the spectrum of the subtraction waveform of the FFR for the 75-dB-SPL pure tone condition in the absence and in the presence of a narrowband noise (84–404 Hz) presented at levels of 86 and 90 dB SPL.

Image of FIG. 4.
FIG. 4.

Mean reduction of peak magnitudes in the FFR, due to the addition of a narrowband noise, at the QDT frequency (spectra of addition waveforms), the frequencies of the CDT, and the primary components (spectra of subtraction waveforms), averaged across conditions with the downward- and the upward-shifted complex. Complex tones were presented at 75 dB SPL. The 300-Hz wide noise had an rms level of 85 dB SPL and was centered on 290 and 310 Hz for the downward- and upward-shifted complex tones, respectively.

Image of FIG. 5.
FIG. 5.

Peak magnitudes at 244 Hz (spectra of subtraction FFRs) for individual subjects for the 244-Hz pure tone presented without a masker, as a function of level. Downward-pointing arrows indicate cases in which the peak value for the time interval when the tone was presented did not exceed the baseline. In these cases, the corresponding (empty) symbol gives the baseline value.

Image of FIG. 6.
FIG. 6.

Excitation patterns for the stimuli in the complex tone conditions calculated using the model of Moore et al. (1997). It was assumed that the sound delivery system had a flat response at the eardrum. Excitation patterns are shown for the complex tone alone (short-dashed line), the narrowband-noise masker alone (long-dashed line), and the two together (solid line). Excitation patterns for the downward- and upward-shifted complexes are shown at the top (a) and bottom (b), respectively.

Tables

Generic image for table
TABLE I.

Stimulus details for all conditions.

Generic image for table
TABLE II.

Effective levels of the cubic distortion product (CDT), defined as the input level of a 244-Hz sinusoid needed to match the spectral magnitude (at 244 Hz) in the FFR response to the downward-shifted complex. The complex tone consisted of three primaries (with frequencies of 544, 844, and 1144 Hz) with a level of 70.2 dB per component. The effective level of the CDT was estimated by linear interpolation from each subject's FFR growth function for a pure tone at the CDT frequency (see Fig. 5). The bottom line gives the mean and the standard error across subjects.

Generic image for table
TABLE III.

Effective level of the quadratic distortion product (QDT), defined as the input levels of a 244-Hz sinusoid needed to match the averaged spectral magnitude (in the addition waveform) of the FFR for the downward- and the upward-shifted complex tones at the QDT frequency of 300 Hz. The downward- and upward-shifted complex tones each consisted of three primaries (with frequencies of 544, 844, and 1144 Hz for the downward shift and 656, 956, and 1256 Hz for the upward shift) with a level of 70.2 dB per component. The effective level of the QDT was estimated by linear interpolation from each subject's FFR growth function for the pure tone at 244 Hz (see Fig. 5). The bottom line gives the mean and the standard error across subjects.

Loading

Article metrics loading...

/content/asa/journal/jasa/132/4/10.1121/1.4751541
2012-10-03
2014-04-19
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Differences between psychoacoustic and frequency following response measures of distortion tone level and masking
http://aip.metastore.ingenta.com/content/asa/journal/jasa/132/4/10.1121/1.4751541
10.1121/1.4751541
SEARCH_EXPAND_ITEM