When Sound Becomes Noise

When Sound becomes Noise

Music to the ears of some can equally be perceived as unwanted, irritating noise to others – as illustrated by a recent news article about a Sydney pub forced to cancel live music on Sunday afternoons after five trouble-free years following a single complaint.

When it comes to industrial equipment like an RB211 gas turbine we can probably all agree that any associated noise is something we would rather do without – unless of course, you happen to be the designing engineer!

Solving these types of noise control problems will usually require the services of a specialist, but how do you go about selecting the company which provides the best fit for resolving the issue? The following tips are designed to help you understand the process and make a better-informed choice.

Firstly, ascertain whether your noise problem relates to the occupational health and safety of employees or the peace and tranquility of the surrounding neighbourhood. Perhaps it’s both, but usually, it’s more one than the other. Determining this will help define the noise criteria and applicable compliance regulations.

There are three key steps to fixing a noise problem related to industrial equipment:

1. Quantify the noise problem and identify its source(s) through rigorous measurement. Identifying the source of the noise is critical to understanding how best to tackle and formulate a detailed noise control design. Surprisingly, the frequency may be too low to detect its source using readily available hand-held instrumentation. Both airborne noise and equipment surface vibration measurements may also be necessary if the noise is travelling via multiple components and materials before escaping into the wider atmosphere.

2. Formulate a noise control solution. The collected data is then analysed to find a solution which addresses the noise as close to the source point as practicable, as this will usually deliver the most cost-effective solution. Solving the problem at source may not be practicable though due to the equipment’s other operating limitations, requiring the adoption of a noise control solution somewhere further away.

3. Pay close attention to detail during the installation of the noise control solution. This is critical. For example, small openings in an equipment enclosure design can easily lead to a doubling of the sound energy being radiated to the outside. For instance, when called in to determine why so much high-frequency noise was passing through a noise barrier at a Brazilian orange juice factory (think very intense nasal experience), INNOVA traced the problem back to poor panel-joint seals.

These three steps are often decoupled through the engagement of different companies for each, leading to misinterpretations within the problem-to-solution life cycle. Consequently the “finished product” may not perform as intended. It is, therefore, better to engage one company to undertake all three to help manage project risk.

Having a single point of accountability also affords you added peace of mind, particularly in INNOVA’s case because we guarantee to meet the specified project outcomes.