The influence of lexical access ability and vocabulary knowledge on measures of speech recognition in noise
Abstract Objective: The main objective was to investigate the effect of linguistic abilities (lexical access ability and vocabulary size) on different measures of speech in noise recognition in normal hearing listeners with various levels of language proficiency. Design: Speech reception thresholds (SRTs) were measured for sentences in steady state (SRTstat) and fluctuating noise (SRTfluc) and for digit triplets in steady state noise (DIN) Lexical access ability was measured with a lexical decision test and a word naming test. Vocabulary size was also measured. For the SRT, keyword scoring and sentence scoring were compared. Study sample: To introduce variation in linguistic abilities, three groups of 24 young normal hearing listeners were included: higher educated native, lower educated native, and higher educated non native listeners. Results: Lexical access ability was most accurately measured with combined results of lexical decision and word naming. Lexical access ability explained 60% of the variance in SRT. The effect of linguistic abilities on SRTs was up to 5.6 dB for SRTstat and 8 dB for SRTfluc. Using keyword scoring reduced this effect by approximately 1.5 dB. For DIN the effect of linguistic ability was less than 1 dB. Conclusions: Lexical access ability is an important predictor of SRTs in normal hearing listeners. These results are important to consider in the interpretation of speech in noise scores of hearing impaired listeners.
International journal of audiology