Usually there tends to be a description connecting the music to a specific kind of emotion, but it could also be a generic music symbol that leaves the person to imagine something in its place. Deaf people can still feel a subset of the vibrations that sound creates (usually the low end bass frequencies played with a higher power output). So a subset of such deaf people may be able to relate to certain sounds with certain emotional content too. The number of humans who cannot hear is a union of two sets – those who were born without the ability to hear and those who could hear but lost it at some point in life. The closed captioning indicators for music leave it to the imagination of the person.