University Communications Sciences and Disorders
Areas of Research
Psychophysics and Signal Processing Laboratory
Jeffery J. DiGiovanni
One of the many consequences of sensorineural
loss is the reduced ability for the auditory system to adequately code
the speech spectrum. It has been shown that this reduction can be
described the broadened auditory filters consistent with sensorineural
hearing loss. One method of at least partially restoring the
representation of a speech signal is through spectral enhancement.
Essentially, spectral enhancement targets peaks in the frequency
spectrum (assumed to be formants) and selectively amplifies these peaks
so the presumed smoothing process of the impaired auditory system
results in a closer-to-normal representation. Multiple studies have
been published on this topic from the APSPL and others are in progress.
One of the primary missions of the APSPL is
and testing signal processing techniques for hearing aids. There are
multiple projects in this category, but the general direction includes
treating the speech stream as a complex and varying stimulus. In that
regard, current projects are aimed at discovering ideal processing
techniques for various speech parts (i.e. phonemes) to maximize
Is the study of the hearing process by looking
we hear in terms of perception and sensation. The intent of
psychoacoustics is to understand the underlying mechanisms of hearing
and how it works.
A secondary focus of the APSPL includes projects
a diagnostic application. Several projects have been completed
including a diagnostic protocol for persons with high-admittance
tympanograms, testing the speed, false-alarm rates, threshold
consistency of various response methods in standard audiomety, and a
case study of a person with a spontaneously recovering sudden
sensorineural hearing loss.