Speech perception in phonology Perceptual mechanisms of sound change Phoneme restoration Compensation for coarticulation Hypo correction Redundancy shift Hyper correction Phonetic variation is a source of possible sound changes There are striking parallels between phonetic variation and common sound changes and synchronic sound alternations Gestural hiding deletion Gestural blending assimilation Aerodynamic voicing constraint devoicing Aerodynamic fricative constraint glide formation But phonetic variation is not the same as sound change left watch as l fwat does not result in sound change ft f why Mechanisms opposing sound change communication is disrupted by sound change social cohesiveness is obtained by phonetic conformity orthographic conventions tend to be standardized processes of perceptual compensation for variation phoneme restoration compensation for coarticulation Phoneme restoration Listen to a short noise burst Now listen to me say legislation Now we put the noise burst over part of the word 1 What is the location of the noise 2 Is the noise added to the word or did it replace part l d noise l e The noise replaces the s and also the voiceless part of the l Did you hear the missing s n Compensation for coarticulation Compare the nasality of the vowel in bam when you hear it with or without the m cut off b m b The presence of the nasal consonant makes the vowel sound less nasalized than when it is cut off This is a sort of perceptual parsing the nasality of the vowel is attributed to the consonant instead of the vowel Listen to them again b m b Which one seems to have the higher vowel This may be another case of perceptual compensation The lower F1 during the nasalized vowel can be parsed as due to nasality when the m is present but may be parsed as an indication of greater vowel height when the m is cut off Processes like phoneme restoration and compensation for coarticulation are perceptual corrections Articulation obscures phonemes and perception recovers them Two kinds of perceptual miscorrections are involved in sound change Ohala 1993 Hypocorrection Listener fails to compensate for context Hypercorrection Listener overcompensates for context Hypo correction Listener fails to compensate for context talker VN VN VN V N listener VN VN V V Note here that articulatory slop coarticulation on the vowel and shortening of the nasal provides input for the perceptual effect but the actual change in the speaker s intention from VN to V is perceptual Redundancy shift Hypocorrection may not be entirely perceptual All phonological contrasts are cued redundantly e g voice is cued by both vocal fold vibration and by pitch on the following vowel The effect of stop voicing on pitch in English Pitch is higher after p than b From Hombert Ohala and Ewan 1979 Redundancy shift Hypocorrection may not be entirely perceptual All phonological contrasts are cued redundantly e g voice is cued by both vocal fold vibration and by pitch on the following vowel Redundant cues are under the speaker s control e g the voice effect on pitch is much smaller in a tone language H M The effect of stop voicing on tonal pitch in Yoruba The pitch perturbation caused by voice is of much shorter duration than in English From Hombert Ohala and Ewan 1979 L Redundancy shift Hypo correction may not be entirely perceptual All phonological contrasts are cued redundantly e g voice is cued by both vocal fold vibration and by pitch on the following vowel Redundant cues are under the speaker s control e g the voice effect on pitch is much smaller in a tone language Two cues for a phonological contrast may gradually shift roles as in tonogenesis voicing primary pitch redundant voicing redundant pitch primary So although hypo correction is an unintended failure of the perceptual process Ohala 1993 redundancy shift may be gradual and set the stage for hypocorrection Hyper correction Listener over compensates for the phonetic effects of context Slavic dissimilation stoj a stoj stand the front vowel a is changed to a back vowel in the context of a front glide j This is a case of hyper correction because the perceptual process of compensation for coarticulation attributes the frontness of the suffix to the glide and thus compensates removes the frontness Many dissimilations have this appearance and typically occur with phonetic properties that have an extended time span Labialization pjam pin diminish Cantonese Glottalization t ant a t anta bread Quechua Pharyngealization C phar V C phar Arabic Another case of hyper correction Perceptual metathesis Blevins Garrett 1998 akekaha a e k aa aakihwaska a ak iwa ska my eye I m buying it Cayuga Cherokee We suppose that kah was realized something like ka h or ka at an earlier stage then the voicelessness of the vowel was reinterpreted perceptually via hyper correction as due to an initial aspirated stop k a Here are a couple of other examples from Slavic orbota olku ti robota la kot work elbow Polish Bulgarian Hypo correction tonogenesis distinctive nasalization perceptual substitution e g w w f with Hyper correction dissimilation metathesis An illustration of hypo and hyper correction Take recordings of he and who Filter them so that only the first formant is audible 500 Hz lowpass filter Put them in a carrier phrase which one has he and which has who 1 or 2 Do they both sound like u after filtering If yes this is an example of hypo correction because you failed to compensate for the filter to restore the F2 of i Now we play the filtered he and who in a filtered version of the carrier phrase Which one has he and which one has who 1 or 2 Do they both sound like i If so this is a case of hyper correction The carrier tells your perceptual system about the filter so now you restore the F2 in both u and i