Hearing-impaired speech deficits stem from using glimpsed information, not spatial processing

Evidence

With two maskers, the difference in thresholds between groups was 11 dB in the natural condition, and 9 dB in the glimpsed mixture condition. For four maskers these deficits were 7 and 9 dB, respectively. In other words, the group differences present in the natural binaural condition were similar when listeners were presented with the good time-frequency glimpses only. In the control condition where the glimpses contained only target energy, the group differences were even larger (12.6 and 10.8 dB). This suggests that the HI deficit is related to the ability to access or use the available target information and not to difficulties with spatial processing or segregation. Individual performance for natural stimuli was strongly correlated with performance for glimpsed stimuli (r = 0.92), again suggesting a common limit on performance in the two conditions. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1753

Performance was better overall with two maskers as compared to four maskers, and for NH than HI listeners. With two maskers, the difference in thresholds between groups was 11 dB in the natural condition, and 9 dB in the glimpsed mixture condition. For four maskers these deficits were 7 and 9 dB, respectively. In other words, the group differences present in the natural binaural condition were similar when listeners were presented with the good time-frequency glimpses only. In the control condition where the glimpses contained only target energy, the group differences were even larger (12.6 and 10.8 dB). This suggests that the HI deficit is related to the ability to access or use the available target information and not to difficulties with spatial processing or segregation. Individual performance for natural stimuli was strongly correlated with performance for glimpsed stimuli (r = 0.92), again suggesting a common limit on performance in the two conditions. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1721

In other words, the group differences present in the natural binaural condition were similar when listeners were presented with the good time-frequency glimpses only. In the control condition where the glimpses contained only target energy, the group differences were even larger (12.6 and 10.8 dB). This suggests that the HI deficit is related to the ability to access or use the available target information and not to difficulties with spatial processing or segregation. Individual performance for natural stimuli was strongly correlated with performance for glimpsed stimuli (r = 0.92), again suggesting a common limit on performance in the two conditions. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1753

Categorization

• XREF: Connects to degraded auditory filtering and glimpsing literature; the claim that masking release failures in HI listeners reflect audibility rather than binaural processing parallels broader themes about bottom-up versus top-down hearing deficits. — 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 (+3 more)
• SEED: Article angle: hearing-loss deficits in cocktail-party hearing persist even when equal audibility is given, pointing toward central rather than peripheral causes.
• corroborated: 9 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 1753; Dijk, Pim van, Physiology, Psychoacoustics and…, 1721

Broader Connections

• Apparent spatial deficits in hearing loss may really be audibility deficits #corroborates (0.85) — Dijk, Pim van, Physiology, Psychoacoustics and…, 1722
• Sound localization deficits in hearing loss come from neural coding changes, not audibility. #contradicts (0.80)
• Hearing aids distort localization cues and often worsen localization #complicates (0.72)