12,000

We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK

93%

93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Differences between psychoacoustic and frequenc...
View graph of relations

« Back

Differences between psychoacoustic and frequency following response measures of distortion tone level and masking

Research output: Contribution to journalJournal article

Published

Journal publication date10/2012
JournalJournal of the Acoustical Society of America
Journal number4
Volume132
Number of pages12
Pages2524-2535
Original languageEnglish

Abstract

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.