What is listening effort?

When speech is heard in the presence of background sound, or when hearing is impaired, the sensory information at the ear is often too ambiguous to support speech recognition by itself. In such circumstances, knowledge-guided processes that help to interpret and repair the degraded signal are required. Such recruitment of cognitive processes is probably why listening in noise “feels” effortful, even when intelligibility is high. Such effort can be aversive, and the goal of making listening less effortful is increasingly recognized as important. In my view, progress in studying listening effort has not been as rapid as one might wish, for several reasons. First, maximizing intelligibility remains the main goal in audiological research, with consideration of listening effort as secondary.  Second, the term is used by some to refer to a listener’s subjective perception of experienced difficulty and by others to refer to a mental process: effort is “deployed”, or “exerted”. Such variable definitions make consistent operationalization impossible - different measures tap fundamentally different phenomena. Finally, for effort to be exerted, a listener has to be motivated to understand – the typical materials used to study effort are arguably not very motivating and may not afford the same cognitive processing as natural speech. In this talk, I will first provide evidence from neuroimaging (fMRI) indicating that even perfectly intelligible degraded speech is processed very differently to clear speech, indicating that it isn’t enough to simply consider intelligibility.  I then provide a framework for how to think about listening effort in a way that may enable research progress, and highlight this with some recent work from my lab demonstrating the use of rich, naturalistic speech materials to study listening behaviour.

To attend the conference and receive the zoom link, contact Olivier Morin, alf.drummond@gmail.com.