Top row: Response likelihood for the two interpretations of an ambiguous fricative at pretest, after /s/-biased exposure, and after /∫/-biased exposure. At pretest (left), the sound was perfectly ambiguous between the two interpretations; following /s/-biased exposure (middle), the sound was perceived as /s/; following /∫/-biased exposure (right), the sound was perceived as /∫/. Middle and bottom rows: These demonstrate that tuning had no effect on perception of unambiguous sounds.