Perceptual Doping: An Audiovisual Facilitation Effect on Auditory Speech Processing, From Phonetic Feature Extraction to Sentence Identification in Noise.

The study compared task order, not practice versus no practice, so it cannot separate the effect of seeing and hearing from repeated task experience. The authors assumed equal procedural learning across the two order groups, and they say this assumption needs a different design to test. The sentence task showed that hearing-only first also improved later seeing-and-hearing scores, so the gain was not only from seeing and hearing. There was no visual-only condition, so the contribution of seeing alone cannot be separated from hearing. The vowel duration task was done in silence, and the authors suggest a ceiling effect may have hidden seeing-and-hearing gains. Cognitive impairment was not fully assessed beyond the Mini-Mental State Examination. The varied consonant contexts in the gated vowel task may have added learning effects. The participants were Swedish-speaking hearing aid users, so the result may not apply to other languages or unaided patients.

The authors declared no conflict of interest. The article is listed as supported by non-U.S. government research.

Do not conclude that seeing and hearing speech is a proven clinical treatment for hearing loss. This study tested task order in laboratory speech tasks, not a rehabilitation programme, and it did not compare practice with no practice.