Classical music provides a theory to this question. This type of music is known to be both relaxing and stimulating depending upon the composer. Language in simply not necessary or complimentary to this style of music. Classical music flows with such precision and drama that know words can fulfill the definition, but if a person is allowed to listen for only a few brief moments they will understand the true meaning. Those of us who can speak take for granted the ability to create and listen to conversations.
Many programs are available to make their disabilities less burdening.
They are still able to be productive in society with out the use of vocal sounds. It is truly difficult to imagine the world with out the spoken word. If the ability to speak was instantaneously removed from the human race chaos and extinction would follow. We as a people have become slave to language we have created.