What is Acoustic Camera Technology and How Does it Work in a Testing Environment?

This noise mapping tool allows for detailed noise source identification analysis

An acoustic camera is used to locate sound sources and to characterise them. It consists of a group of microphones, also called a microphone array, from which signals are simultaneously collected and processed to form a representation of the location of the sound sources.

As part of our assessment process, noise control problems are evaluated, and prototype acoustic solutions are quickly supplied for testing both commercial, agricultural and industrial vehicles. This testing procedure is supported by Ventac’s advanced noise source identification techniques, which include sound intensity equipment and highly effective acoustic camera arrays. This technology combined with our specialised techniques allows us to provide our customers with highly targeted solutions for noise problems.

How Do We Do This?

With the aid of our two state-of-the-art acoustic cameras.

The large acoustic camera array is composed of 1064 individual microphones, and a smaller array of around 60 microphones is handheld and used for measuring smaller sources or cramped environments encountered on vehicles.

The acoustic camera is used for the quick identification of mid to high-frequency noise sources. Live measurements are possible using far-field beamforming (live acoustic camera work) and near-field holography measurements (detailed up close analysis) for detailed analysis of noise radiating from its source at a given frequency. Images can be animated and can record sound for further analysis and to demonstrate the phase or sound wave.

An Intelligent Noise Mapping Tool

The camera is designed to provide qualitative data, in the form of noise maps, rather than the quantitative data a sound meter would provide. Beamforming is a good way of finding the ‘hotspots’ over a large area quickly but it is limited to a relatively high frequency range. Near field holography can measure a very broad frequency range and can map the results in terms of pressure, particle velocity or intensity but is used very close to the noise source and work best on relatively flat structures. The specialised software allows for animated maps of the wave motion for the near filed work and it can display this in a 3-dimensional format. This combination of abilities makes the camera a very powerful noise source identification tool but also one that can provide real insight into the source of noise generation. Ventac’s acoustic technologies are a powerful educational tool for visualising the path and characteristics of the sound.

A wide range of noise sources can be tested using these acoustic cameras. Ventac have typically used it to test passenger vehicles, industrial vehicles, heavy machinery and electronic equipment but this is by no means an exhaustive list and we are consistently surprised by the range of noise problems our customers have. This tool allows us to conduct detailed noise source identification analysis while benefiting customers by providing targeted solutions for noise problems.

Unlike others in the market, Ventac offer a complete noise control solution from analysis to manufacture and supply. At Ventac, we understand how individual acoustic components can contribute to the overall performance of the vehicle and we offer a highly innovative approach to Vehicle and Industrial Noise Control. Ventac take pride in providing solutions that are engineered and designed in-house to specifically address the key noise issues of each individual customer.

Have you heard about the Ventac Lab, Ireland’s largest and only commercial acoustic test chambers?

Ventac acoustic laboratories are used for acoustic materials development, vehicle noise testing and building materials acoustic analysis. Ventac can perform the testing required to bring new products and systems to market or can help in designing and specifying acoustic research and development within our test facilities for the Vehicles and Industrial Industries.

Related reading:

Q&A with R&D Director Mark Simms who answered some questions on an acoustic camera