The theory of phonetic shift is an important part of linguistics.

This word is affected by the sound shift.

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.

After we had a big fight, we became a stronger relationship, just like the proverb 'after the rain, the ground hardens'.

With the spirit of preparing before it's too late, he started studying a week before the exam.

He read the Thousand and One Nights and was drawn to the charm of the Orient.

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