Non-verbal dichotic listening: A new cognitive hearing test for dementia

Central hearing difficulties are a feature of Alzheimer's disease (AD) but not well captured by standard speech perception tests.

We developed a non-verbal dichotic listening test (NVDLT) based on everyday sounds, and compared this with a standard verbal dichotic listening test (VDLT) in 36 people with primary progressive aphasia (PPA), 18 with typical AD (tAD), 6 with right temporal-variant frontotemporal dementia (rtvFTD), and 29 cognitively-healthy controls. Daily-life hearing function was assessed using the modified Amsterdam Inventory for Auditory Disability and Handicap (mAIAD).

On NVDLT, all dementia groups except rtvFTD performed worse than controls; tAD, logopenic-variant PPA and nonfluent/agrammatic-variant PPA performed worse than rtvFTD. NVDLT performance predicted atrophy in the retrosplenial cortex and hippocampus. NVDLT score discriminated tAD patients from controls with near-perfect accuracy (area under the curve [AUC] = 0.99) and predicted daily-life hearing function (r = 0.57).

NVDLT performance indexes daily-life hearing function and may aid dementia diagnosis, potentially in culturally-diverse populations.