One of the many consequences of sensorineural hearing 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 innovating and testing signal processing techniques for hearing aids. There are multipe 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 intelligibility.

Is the study of the hearing process by looking at how 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 with 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.