Sound with intensity larger than 120 dB appears painful to a person. A small speaker delivers 2.0 W of audio output. How close can the person get to the speaker without hurting his ears?

Question

Philoid · Accepted Answer

Given:
The sound level that can hurt the human ear is 120 dB. Then, the intensity is

Audio output of the small speaker
Let the closest distance = .

We have:

⇒

Hence, the closest distance of the human ear from the small speaker is 40 cm.