Why do string instruments have holes?

Answer 1

The main reason a stringed instrument makes sound is that the strings vibrate when strummed, plucked, or bowed and their vibrations create sound waves that you can hear. Instruments like the Violin make sound when bowed because the bow hairs have tiny teeth like structures that pull the strings and makes them vibrate.

The sound waves are then amplified via either the hollow body of the instrument or through electronics.

Answer 2

String instruments have holes so the sound can resonate. The sound waves created when the strings vibrate from being plucked or bowed "bounce around" inside of the instrument body and eventually come out of the hole so the sound can be heard.

Answer 3

The "hollow box" is a resonance chamber. It makes the sound resonate, and easier to hear.

Answer 4

To make the sound hole pick up the vibrations made by strings, it is very important to put them across sound hole. Elsewhere it would not sound that good.