Comparison of Single-Task versus Dual-Task for Listening Effort

BACKGROUND AND OBJECTIVES: Depending on the kind of task and/or material, listeners sometimes need to pay attention to understand communication. The present study aimed to estimate a listener’s amount of effort needed to understand communication by using recognition score and response time as a function of signal-to-noise ratio (SNR) and to confirm his/ her task dependency for listening effort. SUBJECTS AND METHODS: Forty-eight young adults with normal hearing participated in the study. As stimuli, Korean Speech Perception in Noise test without a question tag and three consecutive digits were used for sentence recognition (or single-task) and arithmetic (or dual-task), respectively. Both tasks were measured in quiet and under four SNR (i.e., 0, -4, -8, -12 dB) conditions. Their outcomes were analyzed and compared in terms of percent correct and response time. RESULTS: Sentence recognition scores and arithmetic scores decreased as the level of noise increased. Response time for sentence recognition decreased as noise increased, whereas the response time for arithmetic increased as noise increased. In addition, there was a negative correlation between error percent and response time in the sentence recognition. Conversely, a positive correlation between error percent and response time appeared in the arithmetic test. CONCLUSIONS: Listening effort showed a different pattern based on the kind of task, single vs. dual, while the dual-task required greater effort from the listener.