Young Brunette Girl With A Modern Hi-fi System

Audio equipment must be able to reproduce frequencies high enough and low enough to be realistic. The human hearing range, for healthy young persons, is 20 Hz to 20,000 Hz. Most adults can't hear higher than 15 kHz. CDs are capable of reproducing frequencies as low as 10 Hz and as high as 22.05 kHz, making them adequate, in range, to reproduce all the frequencies that people can hear.
The equipment must also provide no noticeable distortion of the signal or emphasis or de-emphasis of any frequency in this frequency range.