Detection of frequency glides in single tones and single formants: Are tones appropriate analogs of formants in psychophysical experiments?

Abstract

Psychophysical studies of the limits on detection of frequency glides often have used single tones as simple, non-speech analogs of more complex speech stimuli. However, the perceptual equivalence of a single component falling at a nominal formant-peak frequency and a multi-component spectral resonance has not been firmly established. The distinction may be especially relevant when formant frequencies change over time. Detection thresholds for upward and downward frequency change were measured for single-component tonal glides and multi-component spectral resonances as a function of center frequency (500 or 1500 Hz) and duration (30 or 120 ms). The fundamental frequency of the formant stimuli was held steady at 104.5 Hz. The tones were presented at 15 dB SL and the formants were presented at approximately 15 dB SL for a 1/3-octave frequency region around the center frequency. Results suggest that thresholds for frequency glide detection depend on the complexity of the stimuli, as well as stimulus directio...