How is a long vowel sound indicated?

Answer 1

A long vowel sound is indicated by a bar across the top, called a macron.

(because of varying definitions of the long U, normally the OO and YOO are used instead)

Answer 2

A long vowel sound is typically indicated by placing a macron (ˉ) above the vowel symbol, such as in "ā" for the long "a" sound. It can also be indicated by using a silent "e" at the end of a word, which lengthens the sound of the vowel before it, as in "game."