The Effect of Head Movements on Front-Back Discrimination and Sound Externalization With Hearing Aids.
Tobias Greif, Virginia Best, Robert Baumgartner
PMID 42658734WHAT IT FOUND
Hearing aids make it harder to tell if a sound is in front or behind you and to feel it as 'out there' rather than inside your head.
Moving your head while listening helps a lot but does not fully fix either problem.
Key findings
01Both BTE and ITE hearing aids significantly reduced externalization ratings (by 2.26 and 1.73 points respectively) and front-back discrimination accuracy compared to unaided listening, with BTE significantly worse than ITE for front-back discrimination (by 0.59).
02Moving the head during stimulus presentation significantly improved both externalization (by 1.51 and 1.57 points over the two still conditions) and front-back discrimination, but did not fully restore either to unaided levels.
03The relationship between externalization and front-back accuracy varied enormously between the 18 participants, from no significant relationship (r = 0.06) to a very strong one (r = 0.83).
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
All 18 participants had normal hearing, so the findings cannot be directly generalised to the hearing-impaired population who typically wear hearing aids and whose auditory systems interact differently with HA-induced cue distortions. The externalisation rating scale (−10 to +10) implicitly confounds externalisation with distance perception, so some of the reported effects could reflect distance judgments rather than true externalisation. The experiment took place in a low-reverberation sound booth with visible loudspeakers, which does not reflect the reverberant, visually complex environments of everyday listening. The study used a single brand and model of hearing aid with a specific fitting (10 dB linear gain, occluding power domes); results may not generalise to other devices, fitting styles, or non-linear processing settings. The small sample (18 participants, 16 female) limits statistical power and the representativeness of the inter-individual variation observed.
Declared interests
Funded by the Austrian Science Fund (FWF, Grant-DOI 10.55776/I4294), the European Union's Horizon Europe programme (grant 101129903), and the US National Institutes of Health (R01DC015760). The authors declared no potential conflicts of interest.
The easy way to misread this
Do not conclude that head movements fully compensate for hearing-aid-related spatial hearing loss. The study showed a significant improvement but ratings did not return to unaided levels, and the entire experiment was conducted in 18 normal-hearing young adults, not in the hearing-impaired patients who actually wear hearing aids and whose cue processing differs.