G.R.A.S. Sound & Vibration was founded in 1994  located in Holte, Denmark and produces acoustic front-end products such as microphones, preamplifiers and signal conditioning devices. The company has concentrated its efforts and expertise on the development and production of front-end acoustic products. This includes in principle all products necessary for the precise and reliable measurement, and recording of acoustic signals, from the transducer to the input of the A/D converter. The main line of instrumentation includes a broad range of standard measurement microphones and preamplifiers, all designed and manufactured in accordance with international standards. These are complemented by a wide range of more specialised transducers and accessories for more specific applications such as sound intensity microphones, artificial ears, ear and mouth simulators, telephone-testing equipment, HATS, pistonphones and calibrators etc.