Responding to Customer Demands

The Evolution of a Revolutionary Surface Microphone

Brüel & Kjær has pioneered innovative solutions for microphones and preamplifiers for nearly six decades. This heritage of state-of-the-art microphones has resulted in several important microphone innovations.

Recently, Brüel & Kjær launched the groundbreaking Surface Microphone Type 4948 that was developed in close cooperation with Airbus. Type 4948 is flat and small (height: 2.5mm, with built-in preamplifier), supports TEDS and is based on new technology.

Listening to the Customer

It all started when Airbus contacted Brüel & Kjær with a request for an aerodynamic microphone for use during flight tests. The challenge was to produce a microphone that would eliminate the drawbacks of flush mounting traditional microphones – for example, the need to drill a hole in the test object – but with the same measurement performance.

It was realised that a surface microphone with an extremely flat geometry would be the optimal solution. Such a microphone was very different from all other measurement microphones and developing the product required extensive use of numerical modelling. Airbus was involved throughout the development process, verifying the concept and the performance of the microphone. Flight tests have proved that the surface microphone, despite its small dimensions, is corrosion-resistant, and can withstand de-icing detergent and harsh environments, for example, normal aeroplane cruising altitudes of 30,000 feet, turbulence, and hailstorms.

Easy to use, robust, accurate and stable, the Surface Microphone was designed with aerospace requirements in mind, but using decades of microphone technology knowledge and new design ideas.