Acoustic camera by using a microphone array

The acoustic camera uses an array of microphones to precisely localize sound sources. The sounds emitted by a source are recorded by several microphones. The differences in the time of arrival of the incoming sounds (phase position) can be used to draw conclusions about their location and intensity. A color noise map created from these signals is optically superimposed on the photo or video of the object under investigation.

Since these processes take place in real time, the method is particularly suitable for localizing sound sources in moving objects or transient sound events. This makes it possible to detect problematic acoustic sounds quickly and easily on the basis of their specific frequency. Due to a compromise between array dimensions and handling, a disadvantage of this system is that its application is essentially restricted to medium to high frequencies (from approx. 600 Hz upwards). However, by using a near-field probe (HEAD VISOR probe), the application range can be extended to frequencies below 600 Hz, at least for fixed and stationary noises.

Would you like to find out more about the possible applications of the acoustic camera or receive advice on how to localize sound sources in real time? Please contact our scientists directly.
 

Technical specifications

Spiral array with 56 microphones (visor) plus two probe microphones (probe)

Visor:

• Far field analysis
• For sounds approx. 600 Hz upwards
• Stationary and moving measurement objects
• Steady-state and transient processes

Probe:

• Near field analysis
• For sounds 20 Hz upwards
• Fixed objects, stationary noises