Evaluation of the NAL Dynamic Conversations Test in older listeners with hearing loss

Abstract

Objective: The National Acoustic Laboratories Dynamic Conversations Test (NAL-DCT) is a new test of speech comprehension that incorporates a realistic environment and dynamic speech materials that capture certain features of everyday conversations. The goal of this study was to assess the suitability of the test for studying the consequences of hearing loss and amplification in older listeners. Design: Unaided and aided comprehension scores were measured for single-, two- and three-talker passages, along with unaided and aided sentence recall. To characterise the relevant cognitive abilities of the group, measures of short-term working memory, verbal information-processing speed and reading comprehension speed were collected. Study sample: Participants were 41 older listeners with varying degrees of hearing loss. Results: Performance on both the NAL-DCT and the sentence test was strongly driven by hearing loss, but performance on the NAL-DCT was additionally related to a composite cognitive deficit score. Benefits of amplification were measurable but influenced by individual test SNRs. Conclusions: The NAL-DCT is sensitive to the same factors as a traditional sentence recall test, but in addition is sensitive to the cognitive factors required for speech processing. The test shows promise as a tool for research concerned with real-world listening.