G.R.A.S. 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.
 

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.
 

G.R.A.S. Sound and Vibration specialises in:
 

Microphones:

G.R.A.S. is well known for high quality and reliability microphones. They make array, environmental, pressure, outdoor, low noise, probe, random incidence, window and surface microphones   . . . more
 

Preamplifiers:

G.R.A.S. microphone preamplifiers are small robust units optimised for acoustical measurements with condenser microphones   . . . more
 

TEDS Microphones:

IEEE P1451.4 is an emerging standard for adding plug and play capabilities to analogue transducers. Each G.R.A.S. TEDS microphone is a combination of a TEDS-enabled preamplifier and a microphone cartridge which is sealed with   . . . more
 

Power Modules:

G.R.A.S. offers a range of power modules, including: constant current, constant voltage, low-noise measurements and constant voltage and CCP   . . . more
 

Intensity microphones and calibrators:

Sound intensity has both amplitude and direction. The G.R.A.S. sound intensity and microphones and calibrators are   . . . more
 

Intensity Probes:

The intensity-measurement technique is a powerful tool for locating sound sources, order rank them and determine the emitted sound power   . . . more
 

Pistonphones and Calibration equipment:

Measurement of sound pressure and calibration of sound pressure measurement pistonphones   . . . more
 

Telephone test head:

The Telephone Test Head Type 45AA is a tailor-made fixture for testing the acoustic performance of telephone handsets in accordance with international standards   . . . more
 

KEMAR Manikins - Types 45BM and 45BA:

KEMAR Manikin Type 45BM and Type 45BA are head and torso simulators (HATS) based on worldwide average human male and female head and torso dimensions and meet the   . . . more
 

Artificial ears, ear & mouth simulators:

Used in calibration and testing of ear-protection, ear-pieces   . . . more
 

Accessories:

G.R.A.S. Sound & Vibration offers a wide range of standard accessories in the form of cables, adapters, windscreens and tripods for use in measuring set-ups   . . . more
 

Handset Positioning System - Type 45EA:

The Handset Positioning System Type 45EA positions handsets onto KEMAR Manikin Type 45BM. The system features nine moving segments that simulate the human arm, wrist, palm, and fingers holding a handset in the speaking-listening position   . . . more