Listeners’ perception of alaryngeal speech : An experimental study on the effect of presentation and speech mode

Abstract: Individuals with laryngectomy must find a new way of generating voice after the larynx has been removed. In Sweden, the two most common options for this new form of alaryngeal voicing are electrolaryngeal (EL) speech and tracheoesophageal (TE) speech. Only a small amount of research has been conducted on how listeners perceive the speech of individuals with laryngectomy depending on the mode of speech (i.e., EL or TE) and the mode of presentation (i.e., audio only or audiovisual). The current study is one of few examples that aim to fill this gap in the literature. The study aims to examine how Swedish listeners perceive different alaryngeal speech modes (i.e., EL and TE) in both audio only and audiovisual conditions regarding the attributes intelligibility, prosody, speech rate, and listener effort, which were used as dependent variables. The design used for this study was 2´2 repeated measures MANOVA. The data was collected through an online survey, which was answered by 64 individuals. Four different surveys were created to present a randomized order between mode of presentation and mode of speech. One speaker per speech mode was included. The surveys were evenly distributed to the listeners through four links which consisted of 23 questions. Overall, results suggest that TE-speech was rated more favorably than EL-speech in both audio only and audiovisual presentation (mode of speech: p = .000, partial eta squared = .62). The difference between audio only and audiovisual presentation was not as distinct although a preference for the audiovisual presentation could be seen (mode of presentation: p = .00, partial eta squared = .25). Furthermore, no interaction effect between mode of presentation and mode of speech was observed, F(4) = 2.138, p = .09. The effect of mode of speech was statistically significant on all the individual dependent variables whereas the effect of mode of presentation only was statistically significant for intelligibility and listener effort. For those variables, the effect size for mode of presentation was larger than the effect size for mode of speech. However, the results should not be generalized to the larger population due to limitations that are described in the discussion. In addition, the current study provides suggestions for future studies.