NEW YORK (AP) â¿¿ Nielsen-Kellerman is recalling approximately 7,500 microphones because of potential shock or burn hazards. The microphones are made to be used by the navigator of rowed racing boats, which is called a coxswain. The company said Tuesday that the metal boom of the microphone can conduct electricity from an exposed speaker wire or connector and shock or burn the user. The metal booms are not covered by rubber and do not have a yellow warning tag on the cable. Nielsen-Kellerman Co. has received reports of three incidents in which the users reported second-degree burns where the metal boom contacted their face. The recall includes the NK R2 microphones made prior to Sept. 1. They were sold for about $99 at authorized NK dealers and on Nielsen-Kellerman's website. Consumers were advised to stop using the microphones and return them to Nielsen-Kellerman for a free replacement. The company can be contacted at 1-800-784-4221 or (Country Code)-1-610-447-1555 for those outside the U.S. Consumers can also contact the company through their website, www.NKhome.com .