Vowel quantity is distinctive in Hungarian for all vowels. However, the quantity opposition in high vowels has become unstable in colloquial speech. Possible reasons are the low functional load of this distinctive feature and the lack of supporting acoustic cues such as spectral differences between long and short high vowels. According to Ohala’s model of sound change, the quantity neutralisation process in the production of high vowels might go back to a perceptual loss. This was tested in a forced-choice categorisation experiment for high, mid, and low vowels with different age groups. Our results show a decreased
sensibility for high and also mid vowels, but only in unstressed position
