Phased Arrays and the Acoustic Camera
I can almost hear people switching off when they read the words, ‘phased array’ or ‘acoustic camera’. Stick with me though!
The acoustic camera is a device used by acousticians to investigate noise issues in complex environments.
What does it look like? Well, take a look at a few below:
Image Ref – acoustic cameras – https://www.acoustic-camera.com/
The device comes in many varied shapes depending on whether a near or far field is required.
How does it work? A phased array is where several transducers (source or receiver) are combined. Each transducer has a calculated phase difference, making use of constructive and de-constructive interference to create a single, directional wave-front.
Image Ref – Wikipedia – https://en.wikipedia.org/wiki/Phased_array
This allows the sound pressure level across the surface area of the microphones to be mapped. A camera is located in the middle, and the sound pressure is mapped across the image using colour contours.
Image Ref – Norsonic Acoustic Camera
As you can imagine, this equipment is highly specialized, which is often noted in the price. As such, acoustic consultants will use the camera in large schemes, with specific problems.
One example could be when isolating a room from a very high noise environment; such as airport terminals. The acoustic camera could be used to identify areas of weakness in the sound insulation.
This obviously has useful applications in all areas of acoustics, but the high costs associated with the device limit this. In the future, it may be that all consultants carry an acoustic camera with them as standard; reducing investigation times associated with remediation work.
I decided to write about this topic after reading a question on Quora. If you would like to see our reply to this question, or would like to ask us another question about anything noise related, you can here.
You can also check out some of our other content in the Noise Blog.