He is doing exercises to strengthen his genioglossus muscle.

The hyoid muscle is an important muscle that connects the larynx and the tongue.

A back vowel is a sound where the back of the tongue approaches the palate.

Back vowels are vowels that are pronounced using the back of the tongue.

A front vowel is a vowel that is articulated with the front part of the tongue.

The central vowels in Japanese are 'a', 'e', 'o'.

A central vowel is a vowel that is pronounced in the central part of the tongue.

Front vowels are pronounced using the front part of the tongue.

His speech sound is very attractive.

I am majoring in auditory phonetics at university.