Acoustic Sensor Array

Sound Waves: More than Just Noise

© Fraunhofer IFF

Acoustic testing of complex industrial facilities deliver new knowledge and facilitate to better understanding of production systems from machines down to complete production lines. We follow the approach of acoustic emission testing as a building block of multi-sensor data acquisition. We use an acoustic sensor array to localize acoustic emissions. Ultimately, reference acoustic spectra are produced, which, in turn, can be processed into acoustic maps with imaging methods and 3D CAD models. The superimposition of thermographic data adds another dimension. Maintenance use cases in particular can be worked on from the combination of thermography and acoustic measurements since wear is produced by friction, which, in turn, causes noise and generates heat in various spots on a machine.

  • What are you to do when the Federal Immission Control Act requires you to take soundproofing actions?
  • Are you a maintenance technician in need of assistance with recurring tasks?
  • Are you a safety manager who has to assess a manufacturing environment’s compliance with ISO 7731?

Among others, we can provide you these services:

  • noise emissions assessments (not for legal purposes) for acoustically complex environments, e.g. industrial facilities,
  • acoustic signatures for maintenance,
  • inspections of industrial facilities,
  • acoustic work-in-progress assessments,
  • acoustic workspace assessments, and
  • room acoustics, i.e. design of room geometries with obstructions, various materials.

The array: 80 spherical array microphones, measurement distance of 0.5 – 25 m, dynamic range of 35 – 130 dB, dynamic resolution of 0.1 dB, optimum frequency domain (since sensitivity is constant) of 300 Hz – 10 kHz (possible: 20 Hz – 20 kHz), scan rate of 24 to 192 kHz (every channel is individually controllable), distance from sound sources of less than 10 cm

We are also developing a platform that simulates sound waves and electromagnetic waves for use in manufacturing, maintenance and logistics. In close collaboration with us, a client can upload data and conduct simulation studies, modify predefined parameters or customize the simulation model. Then, the results can be downloaded.

A FARO Focus 3D Laser Scanner and the acoustic sensor array enable us to integrate a noise map in a 3D model. We use acoustic simulation
to compare and assess several alternative actions for acoustic damping and insulation. This is expedient for businesses that have been proven to have unduly high noise emissions by an accredited engineering firm and are required by the Federal Immission Control Act to take counteractions. This reveals actions’ impact, e.g. percentage sound level attenuation, even before they have been implemented.

Localization of sound sources with the acoustic sound array.