The Shure SM58 is a professional cardioid dynamic microphone, commonly used in live vocal applications. Produced since 1966 by Shure Incorporated, it has built a strong reputation among musicians for its durability and sound, and more than four decades later it is still considered the industry standard for live vocal performance microphones. The SM58 and its sibling, the Shure SM57, are the best-selling microphones in the world. The SM stands for Studio Microphone.Like all directional microphones, the SM58 is subject to proximity effect, a low frequency boost when used close to the source. The cardioid response reduces pickup from the side and rear, helping to avoid feedback onstage. There are wired (with and without on/off switch) and wireless versions. The wired version provides balanced audio through a male XLR connector. The SM58 uses an internal shock mount to reduce handling noise.