Having no inner voice, imagery, or whatever seems to be poorer rather than richer experience to me. I don't think the existence of deaf people invalidates the importance of music to human experience.
I don't think a deaf person's inability to listen to music with their ears makes them incapable of depth and clarity of thought, no.
I don't think people who aren't hard of hearing necessarily have particularly deep or clear thoughts simply because they listen to music with their ears either. It's very easy to confuse correlation with causation.
(I've specified "with their ears" because deaf people can perceive music through other means than the cochlea + cochlear nerve.)
