PITCH OF NARROWBAND SOUNDS

The objective of this research program is to better understand the pitch
perception of narrowband complex sounds by human observers. The specific
aim of the research includes 1) to examine the validity of the predictions
of two competing models (EWAIF and sewaif) on narrowband pitch, and 2) to
conduct a systematic investigation on the pitch of narrowband sounds. The
EWAIF model derives pitch from an envelope-weighted time average of
instantaneous frequency of the waveform, whereas the SEWAIF model derives
the pitch from a square-of-the-envelope weighted average of instantaneous
frequency. The experimental paradigm requires the observer to match the
pitch of a test stimulus with the pitch of a standard stimulus. The test
stimuli are chosen such that the EWAIF and SEWAIF models predict different
pitch values, an the standard stimuli are chosen such that the two models
predict athe same pitch value. Pitch matching experiments using those
stimuli can determine which model is a better predictor of the data. In
addition to testing between the two models, the proposed study will examine
the effects of stimulus level, center frequency, phases, spectral
bandwidth, envelope fluctuation, and masking stimulus using various
stimuli. A systematic study of the pitch of narrowband sounds will help
hearing scientists to understand pitch perception in more quantitative
detail. The basic information obtained from such studies will expand the
current knowledge about the auditory system and may thus be useful for
diagnosis and treatment of auditory impairment.