Here are the possible solutions for sound that indicates i wonder clue
Answer
Clue
Relevancy
hmm
Clue
Sound that indicates "I wonder ..."
Definition
used to express thoughtful consideration, also HM
huh
Clue
Answer that probably won't earn you any points on a game show unless the prompt is "This one-syllable sound usually indicates someone doesn't know what you're talking about"
Definition
used to express surprise
macron
Clue
Diacritic that indicates a long vowel sound
Definition
(Greek) a symbol placed over a vowel to indicate a long sound
