Using response time to speech as a measure for listening effort.
OBJECTIVE
Speech signals that do not differ in intelligibility might differ in listening effort. This study aimed to investigate the effect of background noise on response time to intelligible speech.


METHODS
We added various amounts of stationary noise to spoken digit triplets and measured the influence of noise on the response time for both an identification and an arithmetic task: Task 1 'identify the final digit in a triplet', and Task 2 'calculate the sum of the initial and the final digits in a triplet.'


METHODS
Twelve normal-hearing participants with a mean age of 30.6 years (range: 28-44 years).


RESULTS
Response time increased with lower (i.e. worse) signal to noise ratios for both tasks, even for signal to noise ratios with almost maximum intelligibility (close to 100%). The response time during the arithmetic task was more affected by the noise than during the identification task, but the arithmetic task demonstrated higher variance.


CONCLUSIONS
The response time to digit triplets reduces significantly for increasing signal to noise ratios, even where speech intelligibility is optimal. These differences in response time might be related to listening effort and as such might be used to evaluate hearing-aid signal processing at positive SNRs.
Clinical and Experimental Audiology, Academic Medical Center Amsterdam , The Netherlands.
Rolph
R
Houben
Maaike
M
van Doorn-Bierman
Wouter A
WA
Dreschler
D000161:Acoustic Stimulation; D000328:Adult; D001302:Audiometry, Speech; D001309:Auditory Threshold; D005260:Female; D006801:Humans; D008297:Male; D009622:Noise / Q000009:adverse effects*; D010470:Perceptual Masking; D011571:Psychoacoustics; D011930:Reaction Time; D017603:Signal Detection, Psychological; D013065:Speech Intelligibility; D013067:Speech Perception; D013997:Time Factors