Fundamental speech. The sound of the talking or singing voice is produced by the vocal cor...

Fundamental speech. The sound of the talking or singing voice is produced by the vocal cords, which are located in an open-ended pipe called to be vocal tract (Fig. P13.65A). Linguists have found that consonant and vowel sounds are comprised of a spectrum of certain emphasized frequencies called formants. The formants for three common vowel sounds are illustrated in Figure P13.65B. (a) Estimate the fundamental frequency of the human vocal tract, assuming that it is about 25 cm long, (b) Consider the harmonics involved in producing the sounds of the vowels of the “oo” as in pool, the “ah” as in father, and the “ee” as in heed. Rank the formants in terms of the fundamental frequency and its harmonic overtones in each vowel sound from the most dominant to the least. The vocal tract changes shape for each vowel, so your calculated frequencies are approximate.

Figure P13.65 A The human vocal tract. B Loudness versus frequency for three common vowel sounds. Gray bands show location of formants.