Possible Clues:

• Individual sounds in a word
• One has one of them, another three
• Speech units
• Piano trio?
• Two of diamonds?
• Lass, belly out of order, giving bits of sound we can understand
• Lass with belly changing? Babies -- there's two there
• They're represented by fingers in charades
• In a word, queen has one, but princess has two of these
• Units of spoken language