Page 38 - Master Handbook of Acoustics

but the lower limit would be 1/6-octave lower than the 1/3-octave, so n = 1/6:

Example 4 What is the frequency of the lower limit of an octave band centered on 2,500 Hz?

What is the upper limit?

In many acoustical applications, sound is considered as falling in eight octave bands, with center
frequencies of 63; 125; 250; 500; 1,000; 2,000; 4,000; and 8,000 Hz. In some cases, sound is
considered in terms of 1/3-octave bands, with center frequencies falling at 31.5; 50; 63; 80; 100; 125;
160; 200; 250; 315; 400; 500; 630; 800; 1,000; 1,250; 1,600; 2,000; 2,500; 3,150; 4,000; 5,000;
6,300; 8,000; and 10,000 Hz.

Spectrum

The commonly accepted range of the audible spectrum is 20 Hz to 20 kHz. This is the approximate

range of frequencies that fall within the perceptual limits of the human ear; the range is one of the
specific characteristics of the human ear. Here, in the context of sine waves and harmonics, we may
establish the concept of spectrum. The visible spectrum of light has its counterpart in sound in the
audible spectrum. We cannot see far-ultraviolet light because the frequency of its electromagnetic