Abstract: The exemplary embodiments herein provide an assembly for transmitting vibrations to a helmet worn by a user, including an annular element adapted to adhere to an outer surface of the helmet. The exemplary embodiments also include an assembly which rotationally connects with the annular element and comprises a bottom housing having a floor, teeth near the floor which engage with the annular element, and a sidewall extending upwardly around the circumference of the circular base unit. The embodiments further include a top housing having an outer sidewall that fits outside of the sidewall of the bottom housing and a plurality of apertures in a top surface; a pressure transducer placed atop the floor; and a mechanical user interface placed above the PCB and having at least one button which extends upwardly and through one of the apertures on the top surface of the top housing.