He stuck out his tongue and licked the ice cream.

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 lingual sound is a sound that uses the tongue when pronouncing.

He stuck out his tongue and licked the ice cream.

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.

In Sanskrit phonology, retroflex sounds play an important role.