Most of the SRM deficit in hearing-impaired listeners stems from reduced audibility

Evidence

Glyde et al. ( 2013 ) showed that even with frequency-specific gain applied according to the individual audiogram using the NAL-RP hearing aid prescription, a strong relationship between SRM and hearing status persisted. The authors noted that with the relatively low presentation levels used in their experiment (55 dB SPL masker), the NAL-RP prescription may not have provided sufficient gain especially in the high frequency region. Thus in a follow-up experiment (Glyde et al., 2015 ), they examined the effect of providing systematically more high-frequency gain than that provided by NAL-RP. They tested HI subjects as well as NH subjects with a simulated hearing loss. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1740

Categorization

• XREF: Connects to the running theme that audibility is only part of what drives spatial release from masking; overlaps with psychoacoustic work on binaural processing and energetic vs informational masking. — connects to: Reduced target audibility, not spatial processing loss, explains much of the hearing-loss speech deficit — Dijk, Pim van, Physiology, Psychoacoustics and…, 1719; Hearing-impaired deficits persist even when only energetic glimpses are presented; Apparent spatial deficits in hearing loss may really be audibility deficits — Dijk, Pim van, Physiology, Psychoacoustics and…, 1722 (+4 more)
• QUESTION: Why did NAL-RP fall short at 55 dB SPL masker — is the insufficiency mainly HF gain limits or loudness discomfort capping real-world gain? Worth chasing the loudness cap interaction.
• corroborated: 3 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 1740

Broader Connections

• Apparent spatial deficits in hearing loss may really be audibility deficits #corroborates (0.95) — Dijk, Pim van, Physiology, Psychoacoustics and…, 1722
• Sound localization deficits in hearing loss come from neural coding changes, not audibility. #contradicts (0.88)
• Audibility is the greatest factor in hearing-loss communication difficulty #corroborates (0.85)
• Hearing loss impairs frequency selectivity beyond what stimulus level differences explain. #qualifies (0.80) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 558
• Hearing-impaired listeners need higher signal-to-noise ratios than normal hearers do #expands (0.72)