Singing is the act of producing musical sounds with the voice, and augments regular speech by the use of both tonality and rhythm. wikipedia.org

Voice acting is the art of providing voices for animated characters (including those in feature films, television programs, animated short films, and video games) and radio and audio dramas and comedy, as well as doing voice-overs in radio and television commercials, audio dramas, dubbed foreign

A transcription service is a business which converts speech (either live or recorded) into a written or electronic text document. Transcription services are often provided for business, legal, or medical purposes. wikipedia.org

Music is an art form whose medium is sound and silence. wikipedia.org

Voice-over is a production technique where a voice, that is not part of the narrative (non-diegetic), is used in a radio, television production, filmmaking or other medium.