Does vowel recognition relate to pitch? Acoustics Virtually Everywhere (AVE), Maurer et al., 2020
	> Close	Method Formant pattern ambiguity for the six natural reference sounds If for a single natural sound of a mid-closed vowel investigated here, Klatt synthesis is conducted based on both its estimated average formant pattern and its calculated average fo level, vowel quality is maintained in synthesis. But if fo is increased by one octave, the vowel quality of the synthesised replica shifts to a closed vowel. This ambiguity phenomenon is illustrated in the following series. Each series presents the natural reference sound, the sound produced with a Klatt synthesiser based on both the formant pattern and fo of the reference sound, and the sound produced with a Klatt synthesiser based on the unchanged formant pattern but with a one octave increase of fo. (For the Klatt synthesiser, see the software reference in the Method.) Series 1: Sounds of /e/. > Sounds Series 2: Sounds of /e/. > Sounds Series 3: Sounds of /ø/. > Sounds Series 4: Sounds of /ø/. > Sounds Series 5: Sounds of /o/. > Sounds Series 6: Sounds of /o/. > Sounds