An echo vowel, also known as a synharmonic vowel, is a paragogic vowel that repeats the final vowel in a word in speech. For example, in Chumash, when a word ends with a glottal stop and comes at the end of an intonation unit, the final vowel is repeated after the glottal stop but is whispered and faint, as in [jaʔḁ] for /jaʔ/ "arrow" (written ya).
In Rukai, echo vowels are pronounced as full vowels but are predictable and disappear when they are under reduplication or when a suffix beginning with /a/ is added to the word:
|echo vowel||wa-uŋulu||uŋul-a||ara uŋul-uŋulu|
|phonemic vowel||wa-kanə||kanə-a||ara kanə-kanə|
Echo vowels are also found in writing, especially with syllabaries. For example, a word kab may be written as if it were kaba, and keb would be written as if it were kebe. Such as system is found in Maya, with complications depending on the quality of the preceding vowel. In Linear B, such final consonants were simply not written. However, consonant clusters were separated with echo vowels: the city of Knossos is written as if it were Konoso (Linear B: 𐀒𐀜𐀰, ko-no-so).
- Paragoge (paragogic vowel)