COGNITIVE AUDIOLOGY: INVESTIGATING THE EFFECTS OF COGNITIVE LOAD AND INDIVIDUAL DIFFERENCES IN COGNITIVE CAPACITY ON HEARING

Abstract

Listening ability is affected by external factors such as background noise and internal factors such as attention-allocation. I varied listening conditions and cognitive load and evaluated auditory word recognition and ratings of listening effort. Additionally, I investigated how individual differences in working memory capacity affected word recognition, recall, listening effort, and how working memory capacity interacted with other factors. Rönnberg et al.’s (2013) Ease of Language Understanding (ELU) model states that individual differences in working memory capacity will lead to differences in language comprehension in challenging listening conditions, where those with higher working memory capacity will be better at speech recognition. Using a dual-task experiment, participants heard and repeated words presented in three listening conditions: masked with pink noise, masked with babble, and processed through a hearing loss simulator. To manipulate cognitive load, participants completed the speech recognition task in both single- and dual-task paradigms. In the dual-task paradigm, participants continuously tracked a pseudo-randomly moving target on a screen for half the experiment. Participants reported perceived listening effort for each combination of listening condition and tracking condition. Additionally, memory for correctly heard words was tested with a recognition memory test. Word recognition performance and listening effort rating data agreed with my hypotheses that difficult listening conditions would produce poorer word recognition performance and increased listening effort. Interesting effects of cognitive load are discussed. The relation between working memory capacity and performance on various measures is also discussed in the context of the ELU model and theories of working memory capacity. Internal and external factors clearly interact to affect listening, and this interaction varies across individuals.