Measuring Listening Effort with Reaction Time to Digits in Noise
Rolph Houben, Inge Brons, Maj Haverkate, Wouter A. Dreschler
Clinical and Experimental Audiology, Academic Medical Center Amsterdam, The Netherlands
Audiological rehabilitation can be beneficial for speech communication even if it does not have a measurable effect on speech intelligibility. For example, single-channel noise reduction is often preferred by hearing-aid wearers, while it does not improve speech intelligibility. We hypothesized that this is caused by an improvement in listening effort. Unfortunately, there is no easy method for the measurement of listening effort. The purpose of the current study is to determine if the measurement of the reaction time to spoken digits in noise can be used to measure listening effort at signal to noise ratios (SNRs) that are high enough to render the speech completely intelligible. We measured reaction times for two tasks. In the first task, participants had to quickly identify the last digit of a triplet (‘identification’). In the second task they had to quickly add the first and the last digit (‘arithmetic’). Three subsequent experiments will be presented, in which we determined (1) if the reaction time to digits increases for normal-hearing listeners when noise is added to the speech, and if the effect of noise is different for the two tasks, (2) if the reaction time to digits in noise is altered by noise-reduction processing for normal-hearing listeners, and (3) if these noise-reduction results are influenced by hearing loss.