Listening effort is a valuable and important notion to measure because it is among the primary complaints of people with hearing loss. It is tempting and intuitive to accept speech intelligibility scores as a proxy for listening effort, but this link is likely oversimplified and lacks actionable explanatory power. This study was conducted to explain the mechanisms of listening effort that are not captured by intelligibility scores, using sentence-repetition tasks where specific kinds of mistakes were prospectively planned or analyzed retrospectively. Effort measured as changes in pupil size among 20 listeners with normal hearing and 19 listeners with cochlear implants. Experiment 1 demonstrates that mental correction of misperceived words increases effort even when responses are correct. Experiment 2 shows that for incorrect responses, listening effort is not a function of the proportion of words correct but is rather driven by the types of errors, position of errors within a sentence, and the need to resolve ambiguity, reflecting how easily the listener can make sense of a perception. A simple taxonomy of error types is provided that is both intuitive and consistent with data from these two experiments. The diversity of errors in these experiments implies that speech perception tasks can be designed prospectively to elicit the mistakes that are more closely linked with effort. Although mental corrective action and number of mistakes can scale together in many experiments, it is possible to dissociate them to advance toward a more explanatory (rather than correlational) account of listening effort.
Bibliographical noteFunding Information:
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was supported by NIH-NIDCD R01 DC017114 (Winn).
The University of Minnesota stands on Miní Sóta Makhóčhe, the homelands of the Dakhóta Oyáte. Data collection was assisted by Emily Hugo, Paula Rodriguez, Lindsay Williams, Hannah Matthys, and Siuho Gong. Valuable input to this project was given by our laboratory participants, as well as Peggy Nelson, Timothy Beechey, Erin O’Neill, Steven Gianakas, and Viral Tejani. Deidentified data are available upon request. Stimulus design for Experiment 1 was assisted by our late colleague Akira Omaki. The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was supported by NIH-NIDCD R01 DC017114 (Winn).
© The Author(s) 2021.
- cochlear implants
- listening effort
- speech intelligibility
- speech perception