Activities and Seminars

Sven Mattys. Impaired speech recognition under a cognitive load: Where is the locus?
Date: May 02, 2013

What: Impaired speech recognition under a cognitive load: Where is the locus?

Where: BCBL auditorium

When: 12 noon

Improving the validity of speech-recognition models requires an understanding of the conditions in which speech is experienced in everyday life. Listening conditions leading to a degradation of the signal – noise, competing talkers, disordered speech – have received most attention in that literature. However, adverse conditions that do not alter the integrity of the signal, such as listening to speech under a non-auditory cognitive load (CL), have been relatively under-studied. Drawing upon behavioral methods including perceptual rating, phoneme categorization, and phonemic restoration, this study attempts to quantify the effects of a concurrent attentional or mnemonic task on listeners’ relative reliance on acoustic cues and lexical knowledge. The methods converge in showing that sensitivity to acoustic detail is reduced under CL and that reliance on lexical knowledge increases. Furthermore, the phoneme-restoration data indicate that the greater reliance on lexical knowledge under CL is a cascaded effect of impoverished phonetic processing, not a direct consequence of CL. The exact locus of this effect is discussed and ways of integrating CL into the functional architecture of existing speech-recognition models are presented.