Page 113 - Master Handbook of Acoustics

FIGURE 5-9 Spectrograph comparison of the harmonic content of woodwind instruments and the
violin playing middle A (440 Hz). The differences displayed account for the difference in timbre of

the various instruments. (AT&T Bell Laboratories.)

Nonharmonic Overtones

Some musical instruments generate a complex type of nonharmonic overtones. Bells produce a
mixture of overtones. The overtones of drums are not harmonically related, although they give
richness to the drum sound. Triangles and cymbals give a mixture of overtones that blend reasonably
well with other instruments. Piano strings are stiff strings and vibrate like a combination of solid rods

and stretched strings. Thus piano overtones are not strictly harmonic. Nonharmonic overtones
produce the difference between organ and piano sounds, and give variety to musical sounds in
general.

Dynamic Range of Speech and Music

The dynamic range of speech is relatively limited. From the softest to the loudest speech sounds, a
voice spoken with normal effort might have a dynamic range of 30 to 40 dB. With more effort, the
range of loud speech might be 60 to 70 dB. Even this range can be easily accommodated by many
audio recording technologies. Music, however, has historically posed a more difficult challenge for
recording and transmission.