و، ب، م all involve the lips, but their manner is distinct. Bāʾ is a stop and can have qalqalah when unvowelled; mīm is intermediate with nasal resonance; wāw flows and can function as madd or līn in the relevant contexts.
Practice بَ، مَ، وَ. Shared geography of articulation does not mean shared sound.
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Wāw, bāʾ and mīm: a shared lip region
Letter-by-Letter Qualities and Distinguishing Features
و، ب، م all involve the lips, but their manner is distinct. Bāʾ is a stop and can have qalqalah when unvowelled; mīm is intermediate with nasal resonance; wāw flows and can function as madd or līn in the relevant contexts.
Practice بَ، مَ، وَ. Shared geography of articulation does not mean shared sound.