What is Acoustic Testing?

Acoustics is the study of noise, sound and vibration. Acoustic testing, therefore, looks at the movement of each of those elements and is often used to test the acoustic performance of products.

Acoustic consulting services play an increasingly important role in assessing any potential or existing offensive noise emitted by plant and equipment and the effectiveness of materials in counteracting that noise. With companies always looking for new ways to beat their competition, having quieter products is one way to give them the edge.

What Noise Assessment Consultants Can Do

Sound is created when the air vibrates and causes sound waves that move through the air. Sounds are louder when vibrations have increased intensity while an increase in vibration frequency results in a higher-pitched sound.

As well as competition from rivals, companies are facing greater regulation to make their products quieter. Various plant and equipment, such as pool pumps, mechanical plant, refrigeration and air-conditioning systems can create loud noises that are distracting and annoying in both commercial and residential environments. Companies are always conscious of maintaining a good brand image and that can be enhanced by having products that operate in a quieter manner than their rivals.

Acoustics are also important for homeowners who want a quiet and restful environment. Acoustic engineering consultants can help both commercial and domestic users by testing various equipment and environments and advising on the best course of action after vibration monitoring.

Acoustic engineers measure acoustic levels and conduct industrial vibration monitoring that includes:

  • airborne and impact sound insulation of various building components
  • sound power level of various devices
  • sound reduction and absorption of particular materials
  • loss factor from specific vibration-damping materials
  • airflow resistance of certain acoustic materials
  • monitoring of plant and equipment, such as excavators during construction to minimise potential cracks and damage to adjacent buildings
  • impact of rail traffic.

Measuring Sound Power Levels

Sound power is measured in watts and is the acoustic energy emitted by a vibrating object. It is not dependent on distance, direction or the environment and results in sound pressure.

Sound power levels are used to:

  • predict noise levels and characterise the source
  • compare and certify the noise from different plant and equipment
  • determine how to reduce noise levels from various plant and equipment.

Testing is typically undertaken in a facility where there are two parallel rooms that are of similar sizes. Each room is isolated from the ground, and they are arranged so that noise only passes through a specimen wall between the two rooms.

An item to be tested is installed in the first room (the source room) and is used to produce different sound waves and noise levels. Tests are undertaken to measure the sound pressure levels in the source room and the second room (the receiving room), background noise sound pressure levels in the receiving room and reverberation times in the receiving room.

These measurements can be processed to determine sound reduction indices. This type of testing is particularly useful to determine the effectiveness of insulating and sound proofing materials, which can be installed in the specimen wall between the two rooms.

The benefits of testing in laboratory conditions are that:

  • it is a completely controlled environment
  • product performance can be replicated accurately in real-life conditions
  • all necessary instrumentation is available and adheres fully to standards
  • testing is undertaken in accordance with ISO 3382-2 and AS ISO 354-2006 for acoustics.

Acoustic testing is crucial to ensure that your company and its products and services comply with regulations and are in line with customer needs.

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