No, it's no longer an acceptable term. "Mute" refers to someone who cannot talk, that is, produce intelligible speech, or someone who has malfunctioning or missing vocal cords. "Mutism" is a medical or psychological condition- the inability or refusal to produce sounds. Virtually all deaf persons are physically and psychologically normal in this area. They have vocal cords and voices, just as the vast majority of hearing people do. This also applied to deaf people who prefer to communicate exclusively in sign language. Their vocal apparatus is perfectly normal. But, being deaf, they cannot hear themselves talk, and thus, cannot easily modulate their voices. Consider: If you were born deaf or became deaf as an infant and have never heard yourself talk, it's extremely difficult to talk clearly, with normal intonation. So signing is the natural mode of communication for many deaf people; speaking can never be. A few deaf people have good clear articulation-better than some hearing people- but most don't. It's a matter of personal preference, deciding what we feel most comfortable with.
Taken from For Hearing People Only: Answers to some of the most commonly asked questions about the Deaf community, its culture and the "Deaf Reality" by Matthew Moore and Linda Levitan