Research output: Contribution to Journal/Magazine › Journal article › peer-review
Differences between psychoacoustic and frequency following response measures of distortion tone level and masking. / Gockel, Hedwig E.; Farooq, Redwan; Muhammed, Louwai et al.
In: Journal of the Acoustical Society of America, Vol. 132, No. 4, 10.2012, p. 2524-2535.Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Differences between psychoacoustic and frequency following response measures of distortion tone level and masking
AU - Gockel, Hedwig E.
AU - Farooq, Redwan
AU - Muhammed, Louwai
AU - Plack, Christopher J.
AU - Carlyon, Robert P.
PY - 2012/10
Y1 - 2012/10
N2 - The scalp-recorded frequency following response (FFR) in humans was measured for a 244-Hz pure tone at a range of input levels and for complex tones containing harmonics 2-4 of a 300-Hz fundamental, but shifted by +/- 56 Hz. The effective magnitude of the cubic difference tone (CDT) and the quadratic difference tone (QDT, at F-2-F-1) in the FFR for the complex was estimated by comparing the magnitude spectrum of the FFR at the distortion product (DP) frequency with that for the pure tone. The effective DP levels in the FFR were higher than those commonly estimated in psychophysical experiments, indicating contributions to the DP in the FFR in addition to the audible propagated component. A low-frequency narrowband noise masker reduced the magnitude of FFR responses to the CDT but also to primary components over a wide range of frequencies. The results indicate that audible DPs may contribute very little to the DPs observed in the FFR and that using a narrowband noise for the purpose of masking audible DPs can have undesired effects on the FFR over a wide frequency range. The results are consistent with the notion that broadly tuned mechanisms central to the auditory nerve strongly influence the FFR.
AB - The scalp-recorded frequency following response (FFR) in humans was measured for a 244-Hz pure tone at a range of input levels and for complex tones containing harmonics 2-4 of a 300-Hz fundamental, but shifted by +/- 56 Hz. The effective magnitude of the cubic difference tone (CDT) and the quadratic difference tone (QDT, at F-2-F-1) in the FFR for the complex was estimated by comparing the magnitude spectrum of the FFR at the distortion product (DP) frequency with that for the pure tone. The effective DP levels in the FFR were higher than those commonly estimated in psychophysical experiments, indicating contributions to the DP in the FFR in addition to the audible propagated component. A low-frequency narrowband noise masker reduced the magnitude of FFR responses to the CDT but also to primary components over a wide range of frequencies. The results indicate that audible DPs may contribute very little to the DPs observed in the FFR and that using a narrowband noise for the purpose of masking audible DPs can have undesired effects on the FFR over a wide frequency range. The results are consistent with the notion that broadly tuned mechanisms central to the auditory nerve strongly influence the FFR.
KW - VENTRAL COCHLEAR NUCLEUS
KW - COMPLEX TONES
KW - BRAIN-STEM
KW - COMBINATION TONES
KW - FUNDAMENTAL-FREQUENCY
KW - PITCH PERCEPTION
KW - RIPPLED-NOISE
KW - PRODUCTS
KW - STIMULI
KW - 2-TONE
U2 - 10.1121/1.4751541
DO - 10.1121/1.4751541
M3 - Journal article
VL - 132
SP - 2524
EP - 2535
JO - Journal of the Acoustical Society of America
JF - Journal of the Acoustical Society of America
SN - 0001-4966
IS - 4
ER -