p469fig12.66 (left column) A schematic of how preserving relative duration, as in the first and third images, of consonant and vowel pairs can preserve a percept, in this case of /ba/, but not doing so, as in the first and second images, can cause a change in percept, as from /ba/ to /wa/, as in the data of (Miller, Liberman 1979) that PHONET simulates.  (right column) Changing frequency extent can also cause a /ba/ - /wa/ transition, as shown in data of (Schwab, Sawusch, Nusbaum 1981) that PHONET also simulates.<BR>||  (left image) Maintaining relative duration as speech speeds up preserves percept (Miller, Liberman 1979).  frequency vs time- [/ba/, /wa/, /ba/]  (right image) Changing frequency extent causes /b/-/wa/ transition (Schwab, Sawusch, Nusbaum 1981). frequency vs time- [/ba/, /wa/] Dt extent.