How will bell's palsy affect my speech?

Depends: Bell's palsy is a peripheral nerve disorder involving the facial nerve usually on one side of the face. The hallmarks are inability to close the eye and droopy upper and lower facial muscles. The speech impairment is dependent on the severity of muscle weakness. The ability to understand speech, follow commands, and write, should be unaffected.

Weak lips and cheek: Bell's palsy affects the muscle of the face. This can affect the lips and the muscle that tightens the cheek. These can affect your speech but fortunately bell's palsy does not involve the tongue.