Answer:
The answer to this is
6600 Hz to 19,800 Hz
Explanation:
The shape of the human ear is analogous to a closed ended pipe hence
we have λ = 4L or wavelength = 4 * length of the child ear
The frequency c/λ where c = speed of sound = 343 m/s
hence the child's audible range is multiples of 343/(4*0.13) =6600Hz
or 13200 Hz or 19,800 Hz
The generally quoted range of human hearing is 20 Hz to 20 kHz
