Measuring the efficiency of listening effort

Listening effort is a commonly reported difficulty among those who have hearing loss. This project aims to operationalize the concept of effort precision, as the ability to engage or disengage mental resources at strategic times could be an important signature of a person’s capacity to guard against wasted effort. Stimuli were designed to simulate the situation of seeking clarification of a misperceived word or attending to specific information in a sentence. Some stimuli included verbatim repetitions (which would ideally elicit reduced effort) and others featured sentences with a masked word followed by a clear repetition (which would ideally evoke effort aimed only at the newly unmasked word). Pupillometry was used as an index of moment-to-moment changes in listening effort. Data showed pupil dilations linked in time with the unmasked word, enabling precise measurements of the efficiency of effort. Listeners with normal hearing displayed the ability to plan and exert effort at specific times while also reducing effort in situations where it was unnecessary. Conversely, listeners who wear cochlear implants generally did not display these efficient effort characteristics. These results highlight the need to expand the concept of listening effort beyond a “more” or “less” framework, toward a framework of efficiency.