Overpressure and breathiness in spastic dysphonia. An acoustic (LTAS) and perceptual study.

Pre- and postsurgical speech segments spoken by patients with spastic dysphonia were submitted to long-time-average-spectrum (LTAS) analysis and for perceptual assessment of breathiness and overpressure. Breathy phonation corresponded to a steep fall in the LTAS, while overpressured phonation produced higher spectral levels and a less steep fall. Mixed breathy-overpressured phonation produced a somewhat elevated spectrum. Post-surgical changes in overpressure are demonstrated by spectral shifts. Perceptual scores correlated well with the objective acoustic spectral measures.