The primary focus of the SVO Lab is investigating auditory-perceptual outcomes for speech and voice, with a particular emphasis on speech that is not well-described using measures of intelligibility. Outcome measures are used to characterize baseline performance and to document change over time. In some cases, a speaker’s intelligibility fails to reflect the amount of effort a listener has to invest in order to communicate with her. It may be less relevant in those cases to verify that a listener has understood the speaker than it is to identify changes in how hard the listener has to work. Measures of perceived listener effort (PLE) capture the listener’s perspective on communicative interactions with an individual with a speech or voice disorder. The SVO Lab collaborates with other labs on studies of perceptual characteristics of disordered voice and speech.

Non-native speakers (NNS) of English often have a different problem with intonation – that is, they are likely to accentuate syllables or words in a way that is distracting to a native listener, which increases the complexity of listening. Frequently, depending on many variables such as native language, NNSs have concomitant problems pronouncing speech sounds in a native-like way. We are interested in the effect that foreign accent has on intelligibility and PLE, but we are also interested in attitudes toward foreign accent. To that end, we are investigating how NNSs address communication breakdowns and what they think of accent modification.

The SVO Lab uses quantitative and qualitative methods to investigate these and other variables related to PLE with the goals of creating valid, reliable measures that reveal the effects of 1) disordered speech and voice on listeners, and 2) the reflection of listener reactions back onto speakers.