Speech intelligibility in quiet and noise environments using speech amplification

and enhancement:  A preliminary assessment of the evaluation protocol

By L. Weiss


Two participants with severe spastic-hypokinetic (P1), and with moderate-severe hypokinetic (P2) dysarthrias were evaluated using the Voicette amplifier and the Speech Enhancer TM 350W and 450 VP. Previously, both participants used amplification for at least a year and were dissatisfied. Both completed a modified course of LSVT and failed to generalize or maintain phonatory effort. Data were obtained for Natural speech, Amplified Speech and Enhanced speech conditions. Data analysis revealed for both participants, Enhanced speech in a quiet environment yielded best results for monosyllabic words and for P1 on words-in-sentences. In a noise environment Amplified speech gave the best results for both subjects on monosyllabic words and for P1 on words-in-sentences. For P2, Natural speech yielded the best result for words-in-sentences in quiet and noise. The results are explained by the variability between and within individuals’ dysarthric speech symptoms. The data suggest that intelligibility scores from an initial evaluation may not be the best predictor for the advantages individuals realize with continued use of the Speech Enhancer™ .