Selective adaptation of vowels

Two experiments investigating the selective adaptation of vowels examined changes in listeners’ identification functions for the vowel continuum [i-I-∈] as a function of the adapting stimulus. In Experiment I, the adapting stimuli were [i], [I], and [∈]. Both the [i] and [∈] stimuli produced significant shifts in the neighboringand distant phonetic boundaries, whereas [I] did not result in any adaptation effects. In order to explore the phonetic nature of feature adaptation in vowels, a second experiment was conducted using the adapting stimuli [gig] and [g ∈ g], which differed acoustically from the [i] and [∈] vowels on the identification continuum. Only [gig] yielded reliable adaptation effects. The results of these experiments were interpreted as suggesting arelative rather than a stableauditory mode of feature analysis in vowels and a possibly more complex auditory feature analysis for the vowel [i].