He is an expert in musicology.

He is an expert in orthoepy, teaching pronunciation.

This room is covered with soundproofing material, so the sound doesn't leak outside.

He honked the car horn to get my attention.

He learned how to operate the anti-tank gun.

His efforts were like a mantis trying to stop a chariot, he couldn't achieve any results.

He is attending school to obtain a motorcycle license.

Infrasound is a type of sound that is inaudible to the human ear.

Debuccalization refers to the phenomenon in phonetics where a specific sound is pronounced outside the oral cavity.

Kunminjōon is a book for teaching the correct pronunciation of Hangul.