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GRAS Sound & Vibration 

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GRAS worldwide

About us

GRAS is a worldwide leader in the sound and vibration industry. We develop and manufacture state-of-the-art measurement microphones and related equipment to industries where acoustic measuring accuracy and repeatability is of utmost importance. This includes applications and solutions for customers within the fields of aerospace, automotive, audiology, consumer electronics, and other highly demanding industries.

GRAS is part of Axiometrix Solutions, a test leading solutions provider comprised of globally-recognized measurement brands.



We were founded in 1994 by Danish acoustics pioneer Gunnar Rasmussen who for more than 60 years has contributed to the world of sound and vibration with his unique ideas and designs. In 1956 Mr. Rasmussen designed the first reproducible 1″ condenser measurement microphone. Mr. Rasmussen’s ingenuity soon led to the world’s most popular and probably most copied acoustic sensor: The 1/2″ measurement microphone. Then the 1/4″ and 1/8″ microphones followed with outstanding dynamic and high-frequency capabilities that made high-definition diagnostics of impulse noise possible. Many variants have been made available over the years, all based on Gunnar Rasmussen’s original 1″ pressure microphone design.


As a privately held company, we safeguard our heritage by constantly striving to push the boundaries of what is possible and help our customers improve their products. This is why we have the industry’s most advanced microphones—a broad range of high-quality microphones for general acoustic applications complemented by an even broader range of highly specialized microphones and test solutions developed and fine-tuned to match specific challenges.

This is a reflection of our unique willingness to help solve our customers’ measurement needs and provide solutions for tomorrow. Listening to our customers is at the core of who we are.


Our measurement microphones are designed to support critical areas in our customers’ R&D, QA and Production Line testing. Using Highly Accelerated Lifetime Tests (HALTs) we ensure that our microphones perform optimally in real-life situations and retain the long-term stability that is crucial for trustworthy measurement results. All our microphones are made in Denmark from stainless steel and in a quality that allows for a 5 year warranty.

GRAS is ISO 9001:2015 and ISO 17025:2017 certified.

Unique Repair Service

Should you by mistake damage the diaphragm on a GRAS microphone, our special technique enables repair at a very reasonable price, ensuring a very low cost of ownership.

Calibration Services

Depending on the use, measurement environment and internal quality control programs, we recommend that microphones are calibrated at a dedicated calibration laboratory at least every second year. We endorse our Accredited Calibration Laboratory in Denmark or the GRAS Microphone Calibration Centers located in Asia, Europe and North America.


GRAS is located in Denmark and represented worldwide in more than 40 countries. Also, we are the preferred supplier of acoustic sensors to a long list of measurement solution providers. Whether you are searching for a multi-channel solution, a replacement microphone or a customized design, your local GRAS partner will in close cooperation with us be able to help solve your measurement needs.

Click here to see the list of GRAS distributors and partners.