Influence of Center Frequency on Preference Evaluation of Bandpass Filtered Speech
Gerhard Martin Sessler, James E. West · The Journal of the Acoustical Society of America · 1971
The subjective influence of the center frequency of bandpass filtered speech samples on preference was investigated. Test stimuli were derived from a single speech sample (male voice). The signal bandwidth was varied utilizing all possible combinations of the lower cutoff frequencies 250, 350, 500 Hz, and the upper cutoff frequencies 3, 4.2, and 6 kHz. The signal was also reverberated with reverberation times of 0.1, 0.2, and 0.3 sec. Listening experiments were conducted with 11 subjects employing a forced-choice paired-comparison method [G. M. Sessler and J. E. West, Proc. Int. Congr. Acoust., 6th, 1968, Paper C-5-8]. A factor analytic technique was used for analyzing the data. It was found that for constant bandwidth (in octaves) and constant reverberation time, the subjective preference was higher for stimuli with low center frequency. For example, stimuli filtered with a 250-Hz to 3-kHz bandpass (bandwith 2.75 kHz) are generally preferred to stimuli with equal reverberation time filtered with a 500-Hz to 6-kHz bandpass (bandwidth 5.5 kHz). The present study thus indicates that, within the above limits, use of low center frequencies results in higher preference and a substantial reduction in absolute bandwidth.