/ay/ continuum

The monophthongization of /ay/ (as in "tide") in American English is a well-studied phenomenon, characteristic of, but not limited to, Southern speech. Below, are synthetic, 7-step continua of /ay/ in the word "guide" by a male and female talker, as used in Plichta & Preston (2004). Note the increasing degree of monophthongization (along F1 and F2) and fronting (along F2) as the continuum progresses.

The stimuli were randomized and repeated four times. At each trial, the respondents were supposed to match the variant of "guide" with a location on the US North-South continuum (see the map below).

The results showed a near perfectly continuous sound-region mapping (see the graph below) despite several subjects' complaints that they were not able to detect any differences among the stimuli. Note that at each step, the female voice was ranked less "Southern" than the male voice.

Plichta, B., & Preston, D. (2004). The /ay/s Have It: The perception of /ay/ as a North-South stereotype in US English. In T. Kristiansen, Coupland, Nikolas, Garrett, Peter (eds) (Ed.), Acta Linguistica Hafniensia (Vol. Theme Issue on Subjective Processes in Language Variation and Change).