Ear-specific selective speech adaptation.

Prolonged exposure to specific speech sounds can induce selective speech adaptation (SSA), which is driven by an early ear-specific/peripheral and a later binaural/central mechanism. We investigated the peripheral/ear-specific SSA component while minimizing involvement of the binaural/central mechanism. In Experiment 1, we exposed participants to monaural left-right alternating Dutch vowels /ø/ and /e/ via headphones (HP), followed by monoaural testing with sounds from an /ø/-/e/ continuum. This procedure induced substantial and long-lasting ear-specific/peripheral SSA. In Experiment 2, we presented dichotic/simultaneous adapters, tested participants with HP or via loudspeakers (LS), and observed that SSA was about four times larger for HP. This was not due to HP generally being more effective in driving SSA, as demonstrated in Experiment 3 with diotic stimuli. The dichotic/simultaneous exposure stimuli themselves, presented through HP, were also not easier to identify (or less ambiguous, Experiment 4), or easier to localize (Experiment 5) when compared with stimulus presentation via LS. HP thus were more effective than LS in separating the ear-specific acoustic input, underscoring the notion that peripheral SSA relies on rather low-level acoustic features of the exposure stimuli. (PsycInfo Database Record (c) 2026 APA, all rights reserved).