Degraded speech delays semantic integration and blocks contextual relief of effort

Evidence

Our results show that processing natural speech comes with a timely integration of semantic information, which in turn reduces lexical competition. Listeners are then able to pre-select a displayed target based on its semantic coherence with the context, and this allows listeners to reduce the effort involved in lexical competition. When processing degraded speech the integration of semantic information is delayed, as is also lexical competition. This implies that semantic integration is not able to reduce lexical competition, which by itself is longer and occurs later. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3953

This present study examined the effect of semantic integration on the time course of lexical competition, and on the effort involved in solving lexical competition in natural and degraded speech. Our results show that processing natural speech comes with a timely integration of semantic information, which in turn reduces lexical competition. Listeners are then able to pre-select a displayed target based on its semantic coherence with the context, and this allows listeners to reduce the effort involved in lexical competition. When processing degraded speech the integration of semantic information is delayed, as is also lexical competition. This implies that semantic integration is not able to reduce lexical competition, which by itself is longer and occurs later. These results were also mirrored by the pupil dilation data, in which a release from lexical competition was visible but delayed. Mapping of degraded speech to mental representations is more effortful due the mismatch between the actual signal and its mental representation, and lexical context is not able to release listeners from this effort on time. In natural situations, in which words are being heard in succession, and the speech signal evolves quickly over time, such a difference in processing speed of degraded speech will accumulate effort, and draw more strongly on resources in working memory. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3995

Categorization

• XREF: Connects to the reader’s noise-library theme: degraded signals (noise, degradation) change cognitive processing timing, echoing how altered percepts alter downstream interpretation. — connects to: Signal degradation delays semantic integration and raises listening effort — Dijk, Pim van, Physiology, Psychoacoustics and…, 3951; Semantic knowledge helps listeners interpret degraded speech signals; Degraded speech processing raises baseline cognitive effort independently of semantic context — Dijk, Pim van, Physiology, Psychoacoustics and…, 3978 (+1 more)
• QUESTION: Worth chasing: does this delayed-integration effect for degraded speech interact with hearing-aid signal processing that itself introduces degradation?
• corroborated: 6 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 3953; Dijk, Pim van, Physiology, Psychoacoustics and…, 3995

Broader Connections

• Semantic-context benefits to word recognition vanish under signal degradation #contradicts (0.82)
• Degraded speech processing raises baseline cognitive effort independently of semantic context #expands (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3978