Reduced target audibility, not spatial processing loss, explains much of the hearing-loss speech deficit

Evidence

Hearing loss has been shown to reduce speech understanding in spatialized multitalker listening situations, leading to the common belief that spatial processing is disrupted by hearing loss. This paper describes related studies from three laboratories that explored the contribution of reduced target audibility to this deficit. All studies used a stimulus configuration in which a speech target presented from the front was masked by speech maskers presented symmetrically from the sides. Together these studies highlight the importance of adequate stimulus audibility for optimal performance in spatialized speech mixtures and suggest that reduced access to target speech information might explain a substantial portion of the “spatial” deficit observed in listeners with hearing loss. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1719

In summary, increasing SL improved performance and increased SRM for all listeners. Furthermore, careful equalization of audibility across listeners reduced the effects of hearing loss on SRM. On the other hand, no manipulation was able to guarantee equal performance across listeners with various degrees of hearing loss. This suggests that while audibility is clearly an important factor, other factors may impact speech-in-speech intelligibility (e.g. aging, auditory filter width, or comorbidities associated with cognition, working memory and attention). — Dijk, Pim van, Physiology, Psychoacoustics and…, 1739

Abstract Hearing loss has been shown to reduce speech understanding in spatialized multitalker listening situations, leading to the common belief that spatial processing is disrupted by hearing loss. This paper describes related studies from three laboratories that explored the contribution of reduced target audibility to this deficit. All studies used a stimulus configuration in which a speech target presented from the front was masked by speech maskers presented symmetrically from the sides. Together these studies highlight the importance of adequate stimulus audibility for optimal performance in spatialized speech mixtures and suggest that reduced access to target speech information might explain a substantial portion of the “spatial” deficit observed in listeners with hearing loss. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1719

Categorization

• XREF: Connects to the broader picture that cognitive factors (working memory, attention) influence speech-in-noise perception independent of audibility, matching reading interests in cognition alongside psychoacoustics. — connects to: Apparent spatial deficits in hearing loss may really be audibility deficits — Dijk, Pim van, Physiology, Psychoacoustics and…, 1722; Hearing-impaired speech deficits stem from using glimpsed information, not spatial processing — Dijk, Pim van, Physiology, Psychoacoustics and…, 1753; Sound localization deficits in hearing loss come from neural coding changes, not audibility. (+8 more)
• QUESTION: What exactly are the non-audibility factors — is auditory filter width or cognitive aging the dominant residual driver when audibility is equated?
• corroborated: 8 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 1719; Dijk, Pim van, Physiology, Psychoacoustics and…, 1739

Broader Connections

• Apparent spatial deficits in hearing loss may really be audibility deficits #corroborates (0.95) — Dijk, Pim van, Physiology, Psychoacoustics and…, 1722
• Most of the SRM deficit in hearing-impaired listeners stems from reduced audibility #corroborates (0.92) — Dijk, Pim van, Physiology, Psychoacoustics and…, 1740
• Sound localization deficits in hearing loss come from neural coding changes, not audibility. #contradicts (0.90)
• Hearing-impaired speech deficits stem from using glimpsed information, not spatial processing #corroborates (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 1753