Question

which of the following sound frequencies cannot be heard by a human ear​

Answer 1

Answer:

20 to 20,000Hz 

Explanation:

While 20 to 20,000Hz forms the absolute borders of the human hearing range, our hearing is most sensitive in the 2000 - 5000 Hz frequency range. 

Answer 2

Answer:

Lower Than 20Hz

Explanation:

The range of hearing for a healthy young person is 20 Hz to 20,000 Hz. This is called audible range of frequency.