The median frequencies of the first and second formant of oral Navajo vowels plotted in a chart. The formant data is from McDonough (2003).

The graphing the first and second formants of a vowel roughly corresponds to its perceived location on a vowel chart.

First formant (F1) is plotted against the difference between the second and first formants (F2-F1). Formant measurements are in Hz. The frequencies have been converted to a mel scaling (the equation is ${\displaystyle mel=(1000/\log _{10}2)(\log _{10}(1+frequency/1000))\ }$, which is from Fant (1968)).

The F2-F1 vs. F1 plotting (over a F2 vs. F1 plotting) is suggested by Ladefoged (1993). The mel scaling suggestion is from Ladefoged (1967). McDonough's median formant values are here:

Oral Vowels

Vowel	F1	F2		Vowel	F1	F2
iː	372	2532		oː	513	957
i	463	2057		o	537	1154
eː	487	2195		aː	752	1309
e	633	1882		a	696	1454

Bibliography:

• Clark, John; & Yallop, Colin. (1995). An Introduction to phonetics and phonology (2nd ed.). Oxford: Blackwell.
• Fant, Gunnar. (1968). Analysis and synthesis of speech processes. In B. Malmberg (Ed.), Manual of phonetics (pp. 173-177). Amsterdam: North-Holland.
• Ladefoged (1967). Three areas of experimental phonetics. London: Oxford University Press.
• Ladefoged (1993). A course in phonetics (3rd ed.). Fort Worth: Harcourt Brace College Publishers.
• McDonough, Joyce. (2003). The Navajo sound system. Dordrecht: Kluwer Academic Publishers.

• Image:NavajoVowelFormantsMcDonough1993.png

I, the copyright holder of this work, hereby publish it under the following license:

This file is licensed under the Creative Commons Attribution 3.0 Unported license.

You are free:

• to share – to copy, distribute and transmit the work
• to remix – to adapt the work

Under the following conditions:

• attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.

https://creativecommons.org/licenses/by/3.0CC BY 3.0 Creative Commons Attribution 3.0 truetrue