Acoustic characteristics of speech produced with an electronic artificial larynx

This study investigated the acoustic characteristics of speech produced with an electronic artificial larynx (electrolarynx). Five normal‐speaking adult males were taught to use an electrolarynx, and each talker recorded a set of speech materials in his normal voice and with an electrolarynx. The recordings were subjected to analyses which included: (1) intensity level measurements of speech as well as the direct radiated sound from the electrolarynx; (2) speech‐duration measurements; (3) spectral analysis of the radiated masking sound from the electrolarynx; and (4) formant frequency estimates derived from the spectrum of a linear prediction inverse filter. Results indicated that the overall intensity of electrolarynx speech was similar for the five talkers, but that intensity of the radiated noise, and hence speech‐to‐noise ratios, varied considerably among talkers. In addition, talkers required about 50% more time to produce speech with an electrolarynx, indicating modification of articulatory behavior. Spectral composition of the radiated sound from the electrolarynx varied from talker‐to‐talker. Formant frequencies for a given talker were similar for the normal voice and the electrolarynx productions, but the intensity relationships between formants was different in the two modes of production. [Research supported by NINCDS and a grant from the Samuel W. Traylor Foundation.]