Talk:Formant
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[edit] Throat Singing
I added the paragraph on throat singing, but didn't realize I was logged out.--Theodore Kloba 22:37, Dec 16, 2004 (UTC)
should have spectrogram images. - Omegatron 17:45, Jan 26, 2005 (UTC)
[edit] Vowel charts
The list of frequencies for various vowels has two major problems that concern me. The first is that the anon who first added them didn't cite any source. More importantly, though, it uses orthography rather than IPA values when showing the vowels. It doesn't even say what language those vowels occur in (the only language I've found that uses all of <ä>, <ö>, <ü>, and <å> is Finnish, but it doesn't use <å> in any native words, and I don't know how it's pronounced in the words borrowed from Swedish anyway; these symbols have significantly different pronunciations in the different languages in which they occur). Does anyone know what the phonetic values of these vowels are intended to be? --Whimemsz 01:12, 23 January 2006 (UTC)
- Finnish actually doesn't use ü (they use 'y' for the close front rounded vowel, the same as in IPA). I guessed that ü was y, so if the person that posted that intended something other than y, please correct it. Also, I changed the vowels from capital to lower case because there is a difference in IPA between i and I, for example. (Technically, it's i and ɪ, I know.) In Finnish, ä is IPA æ, ö is ø. I've always heard Swedish å realized [o]. I guessed which IPA vowel 'å' was supposed to be based on the formant frequencies and changed it to ɑ. The changes, however, may not be right because å, ä, ö and ü vary from language to language (hence IPA).
- Also, if there are sources for these formant frequencies, I'd like to see them. I have Peter Ladefoged's A Course in Phonetics (4e, p 172) in front of me and the numbers listed for F1 and F2 of some of the vowels are quite different (ie the number listed for F2 is closer the Ladefoged's F3 number on [i]). Sources/suggestions? JordeeBec 19:32, 9 March 2006 (UTC)
I am also concerned about the vowel charts. First, the two charts seem rather redundant - better (imho) to go with a single chart that incorporates what both of these charts are trying to do: list approximate frequencies of the first two formants and indicate the range of variation. Second, The frequency of the second formant given for [i] in both charts seems too high, and is probably actually the third formant frequency (the other formant frequencies are in the right ballpark - but of course there is the issue already mentioned about variation from language to language, getting the IPA symbols right, and variation from utterance to utterance for a given speaker). Third, the second chart's "main formant regions" (only one for back vowels, but two for front vowels) are related to auditory processing of vowel acoustics, and not to the acoustics themselves. Since this page is specifically about formants, I suggest sticking with the actual formants rather than main formant regions. Lulich 02:07, 26 May 2006 (UTC)
[edit] Introduction
I find the first line confusing. Please could someone make this clearer.
[edit] Formants in sonorants vs. obstruents
The article makes some incorrect statements about what kinds of sounds formants belong in. For instance, "Not all sounds used in human language are composed of formants. Formants are restricted to sonorants [...]". Since formants are basically resonances of the vocal tract, they are always present regardless of the type of sound being produced. The distinction between sonorants and obstruents (and various gradations between) concerns the means of exciting the resonances - whether by periodic voicing (in vowels) or by noise (in fricatives), for instance. "Note that fricatives always lack formant structure and are distinguished by the frequency range with the most noise, as well as overall strength of frication." Fricatives actually do have formant structure. For instance, [S] and [s] are largely differentiated by the strength of the 3rd formant. The fact that certain frequency ranges have more noise than others (depending on the fricative) is derived from the location of the noise source within the mouth. For [s] it is near the teeth, so that low formants (resonances) belonging to the back of the mouth (behind the source) are not excited much - this is in contrast to vowels, in which the periodic voicing source is at the larynx so that all of the formants are excited strongly. Check out Ken Stevens' book Acoustic Phonetics for confirmation. Lulich 02:07, 26 May 2006 (UTC)
[edit] Spectrogram
I have a problem with the spectrogram. It represents three sounds that don't change through time, and yet the time resolution is quite high, definitly overkill, and because of that, the frequency resolution is very poor, as it's really all that matters (so much that we could content ourselves with the magnitude part of the DFT of these sounds). That'd be cool if someone could do it again with a much lower time resolution.
Also due to the nature of speech it wouldn't be bad if the frequency scale was logarithmic (base 2 of course)
