The next resonance region will be around 1500 and 2500 Hz. Thus, as in the case of all musical instruments, the voice does not have the same quality over its complete range of frequencies. Its harmonic spectrum varies with frequency. Figure 7.20 shows a typical harmonic spectrum for the human voice at several different frequencies. The harmonic spectrum of the human voice at various frequencies.
Some people are able to name the pitch of a sound to less than a semitone.
It seems to be a hereditary trait as opposed to one that is learned. Whatever its cause, it is certainly cherished by those few musicians who have it. All wind instruments consist of a sound generator and a resonant air column. As water is poured into a soda bottle the pitch of the sound produced increases as the water level increases. An organ pipe has a pitch of C 4 in air.