Abstract

Tracheoesophageal (TE) speech is the most frequently used voice restoration technique after total laryngectomy. Despite being often cited as the alaryngeal speech alternative most comparable to normal, its quality and intelligibility are still significantly lower than laryngeal speech. Excitation and prosodic deviations are thought to be the main limitations responsible for its quality reduction. This seminar will describe excitation and duration repair systems developed for the enhancement of continuous TE speech. The excitation repair system resynthesises TE speech using a synthetic glottal waveform, reduces its jitter and shimmer and applies a novel spectral smoothing and tilt correction algorithm. For duration repair, TE phone durations are modified based on the predictions of regression trees built from non-pathological data. The perceptual enhancement of each system is evaluated using listening tests. Results show that the repaired sentences are preferred to the original overall in terms of breathiness, harshness and rhythmic naturalness.