Functional (speaker-based) and non-functional (listener-based) accounts are often equally satisfactory in explaining internally motivated diachronic sound change. Here we report a case clearly favoring the non-functional account: In some dialects of English, /æ/ is raised before /g/ but not /k/. The raising may be an attempt to reduce the conflict between producing the low front vowel before the voiced velar, or it may be due to listener misapprehension. Using acoustic and articulatory data from General American English to simulate the conditions prior to /æ/-raising, we show the precipitating stimulus for /æ/-raising had to have been listener misapprehension. Specifically, even though both /g/ and /k/ exert a coarticulatory effect on /æ/, acoustic evidence for the coarticulatory effect is found only before /g/.