Glossary / Lexicon
Phoneme boundary effect
        Phoneme boundary effect refers to the phenomenon in which the same acoustic difference,  such as a 20-millisecond difference in voice onset time (VOT)  is perceptible if the two (2) st 
imuli are on opposite sides of a phoneme boundary (as in B versus P) but is imperceptible if the two (2) stimuli are within the range of variation perceived as one phoneme. See also Categorical perception.     
        
        
                                        