How many octaves does normal human hearing span? How many octaves are on a common piano keyboard? (If you’re not sure, look and see.)

Solution 33E Part 1 The octave is defined as the interval between one frequency and its double. The audible frequency range is 20 Hz to 20000 Hz. Now if the audible range is spanned over n octave, then we must have Hence the audible frequency is spanned over a range of 10 octave. Part 2 The frequency of a piano keyboard is spanned over a range of 8 octave.