When studying pronunciation, long vowels can alter the meaning of otherwise identical words.

In phonetics class, the teacher asked us to hold a long vowel at roughly one and a half to twice the duration of a short vowel so we could observe the contrast.

When teaching Japanese pronunciation, she used long-vowel marks to show which syllables should be held longer.

In phonetics class, the instructor showed how to write the long-vowel mark ː after a vowel to indicate its length.

In phonetic transcription, the half-long vowel is indicated by a length mark slightly shorter than the symbol for a long vowel.

In phonetic transcriptions, half-long vowels often serve to distinguish subtle timing contrasts between short and long vowels.