Utility of Perceived Listener Effort as an Outcome Measure for Disordered Speech and Voice

Abstract

Listening effort is a concept that has been shown to be clinically useful measuring hearing outcomes. Given the potential effects of disordered speech or voice on normal-hearing listeners, the effort required to listen to such speech may be worth evaluating for disordered speech as well. This document includes a review of the literature (Chapter 1) on objectively measured listening effort and subjectively measured <italic>perceived listener effort<italic> (PLE), specifically to determine the utility of PLE ratings for disordered speech and voice. Following this review, three studies are described in which PLE is compared to current outcome measures (i.e., speech acceptability and intelligibility) using tracheoesophageal (Chapter 2) and electrolaryngeal (Chapter 3) speech samples. Despite strong correlations among the measures, ratings of PLE were shown to differ significantly depending on sentence length (number of words), whereas ratings of acceptability and intelligibility did not. Qualitative data reviewed in Chapter 4 revealed similar interpretations of the terms “acceptability” and “listener effort” by everyday listeners; “understandability” was reported as a major component of both. However, listeners described differences between the concepts as well. Acceptability was interpreted as pleasantness, whereas PLE was specifically how difficult it was to listen to the speech samples. Findings support continued research into the factors affecting PLE and how best to measure it for evaluations of disordered speech and voice.