Mario J. McNulty is an American Grammy Award-winning record producer and audio engineer based in New York City, United States. He has worked with David Bowie, Prince, Nine Inch Nails, The B-52s, Julian Lennon and many other well-known recording artists. At the 50th Annual Grammy Awards, along with artist Angélique Kidjo and producer Tony Visconti, McNulty won a Grammy in the Best Contemporary World Music category for the album Djin Djin (2007). Other Grammy-nominated albums include Homeland by Laurie Anderson in 2009 and Bowie's The Next Day in 2013.

An audio engineer helps to produce a recording or a live performance, balancing and adjusting sound sources using equalization, dynamics processing and audio effects, mixing, reproduction, and reinforcement of sound. Audio engineers work on the "technical aspect of recording—the placing of microphones, pre-amp knobs, the setting of levels. The physical recording of any project is done by an engineer…"