Starting with the kind of growl that singers like Bono use relatively effectively to lead up to a note in a pop song - a la, " slight of hand and twist of fate, on a bed of nails she makes me wait," but that can be used to egregiously ill-effect, a unit of measurement should be established that standardizes the effectiveness of these vocal growls. I have the feeling that this will be both hard to do and interesting, because 1. It is a standard technique, 2. It feels effective to me at some times and other times grossly ineffective, and, 3. some other people don't agree with me about the effectiveness of specific examples of this vocal growl technique - which makes me think that it is not just aesthetics and opinion going on here but a specific kind of hearing blindness/hyper-sensitivity that is clouding the possibility of standardization of agreement on the effectiveness of these vocal growls.
Eventually this kind of measurement could be used to score and then optimize what will surely turn into purely a vocal musical genre.-- JesusHChrist, Dec 19 2013 With or without you http://m.youtube.co...h%3Fv%3DXmSdTa9kaiQ [JesusHChrist, Dec 19 2013] By the title I thought I would have something to contribute, but I don't.-- Alterother, Dec 19 2013 Oo forgot to add that you could pretty simply base it on the shape of pitch over time, clicks per second, things like that. And as to the genre, there is already a pretty extensive collection of YouTube videos on, "how to growl", although the use of "growl" there is not exactly the same as I mean.-- JesusHChrist, Dec 19 2013 + for measurement!
In perusing some YT videos, it seems that growl /fry type vocalizations use a variant of vocal fold constriction followed by strong formant generation created by lengthening the vocal tract (extended lips, etc.)
Comparing audio spectra and extraction of various key elements should do the job.-- csea, Dec 19 2013 measure the non-harmonic content of vowels. I think you mean "rasp".-- FlyingToaster, Dec 19 2013 random, halfbakery