GRAS Sound & Vibration was founded in 1994 by Gunnar Rasmussen and is a 100% privately owned company. This Danish company produces acoustic front-end products such as microphones, preamplifiers and signal conditioning devices.

Gunnar Rasmussen is well known for his numerous contributions to the development of noise and vibration measurement instrumentation. With more than 50 years in the industry he has developed a number of key products such as modern measurement microphones, sound level meters, sound intensity probes, delta shear accelerometers and many others. He has also worked with precision, free-field and pressure reciprocity calibrations, as well as pistonphone and laser calibrations.

GRAS 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.