If you are dealing with a noise problem, it can be difficult to know what type of acoustic investigation you actually need. Should you measure the noise level with a sound level meter, or use an acoustic camera to find out where the sound is coming from?
The two technologies are used for different purposes. A sound level meter measures how much sound is present at a particular location, while an acoustic camera helps identify where the sound is coming from. In some investigations, one is enough. In others, using both can provide a much clearer picture of the problem.
What Does a Sound Level Meter Do?
A professional sound level meter is used to measure sound pressure levels at a specific location and over a defined period. Depending on the type of investigation, measurements can include parameters such as equivalent continuous sound level, maximum sound levels and frequency information.
This makes sound level measurements useful when the main question is “How loud is the noise?” For example, measurements can be used to investigate environmental noise, equipment noise, traffic noise or noise affecting a neighbouring property. The results can then be assessed using the relevant standards, regulations or project requirements.
A sound level meter can tell you that the noise level at a particular location is high, but a measurement at that location does not necessarily tell you exactly which part of a machine, building or installation is responsible.
What Does an Acoustic Camera Do?
An acoustic camera approaches the problem from a different direction. It uses multiple microphones arranged in an array together with digital signal processing to analyse where sound is coming from. The acoustic information can then be combined with a visual image to create a noise map showing the areas that are contributing most strongly to the measured sound.
This makes an acoustic camera particularly useful when the source of a noise problem is unclear. Instead of simply knowing that a machine, installation or structure is noisy, you can investigate which part is producing or radiating the strongest sound.
For example, an acoustic camera can be used around industrial machinery, ventilation systems, pumps, compressors and other equipment where several potential noise sources may be operating at the same time.
The Simple Difference: How Loud or Where From?
The easiest way to understand the difference is to think about the question you are trying to answer.
If you want to know how loud something is, a sound level measurement is usually the appropriate starting point. If you want to know where the noise is coming from, an acoustic camera can provide information that a conventional sound level measurement cannot provide on its own.
Imagine that several machines are operating in the same production area. A sound level meter can show the overall noise level at a particular position, but it may not be immediately obvious which machine or component is contributing most to the result. An acoustic camera can help visualise the dominant sound sources and direct the investigation towards the areas that require attention.
When Do You Need a Sound Level Measurement?
A sound level measurement is generally appropriate when you need reliable information about the level of noise at a particular location.
This can include environmental noise from roads, industrial sites or other external sources; noise from mechanical equipment; workplace or building investigations; and situations where you need to compare measured noise with an applicable limit or technical requirement.
The measurement can also be carried out over a longer period when noise changes throughout the day or night. This is important because a short measurement may not represent a noise source that operates intermittently or changes significantly over time.
If your main concern is proving or documenting the noise level at a particular location, a properly planned professional noise measurement is usually more relevant than simply locating the source visually.
When Is an Acoustic Camera More Useful?
An acoustic camera is particularly useful when you can hear or measure a noise but cannot determine exactly where it is coming from.
This can happen with industrial equipment, ventilation systems, pumps, compressors, machinery and other complex installations. Several components may produce sound at the same time, making it difficult to identify the main contributor by listening alone.
An acoustic camera can help visualise the sound field and identify areas that are radiating more noise than others. This can make troubleshooting more targeted, because instead of investigating an entire machine or installation, attention can be focused on the components or areas identified during the acoustic investigation.
Can an Acoustic Camera Find Noise Leaks?
Yes, acoustic cameras can be useful for identifying areas where sound is escaping or where a structure is radiating more sound than expected.
For example, if a noisy room is separated from a quieter area by a wall, an acoustic camera can help identify sections of the wall, doors, windows, penetrations or other areas that may be contributing to sound transmission or radiation.
However, an acoustic camera does not replace a formal building acoustic measurement. If the objective is to determine the sound insulation performance of a wall, floor or other separating structure, the appropriate building-acoustic measurement method should be used.
The acoustic camera can instead be a useful additional tool when the investigation needs to establish where a particular sound is entering, escaping or being radiated.
Can a Sound Level Meter Identify the Noise Source?
A sound level meter can provide useful information about the level and characteristics of noise, but it is not primarily designed to create a visual map of where the sound originates.
A specialist can take measurements at different locations and use those results to investigate the source, but this can become more difficult when several sources are operating simultaneously or when sound is being transmitted indirectly through a building or structure.
An acoustic camera can make this part of the investigation easier by providing a visual representation of the strongest acoustic sources. It does not mean that every noise investigation needs an acoustic camera, but it can be particularly valuable when the source is difficult to isolate.
Do You Ever Need Both?
Yes. In more complicated investigations, a sound level meter and an acoustic camera can complement each other.
An acoustic camera can help identify the dominant source, while sound level measurements can be used to quantify the noise at the relevant locations and assess it against the applicable requirements. Once a potential source has been identified, further measurements can also be used to investigate the problem or evaluate whether a repair or noise-control measure has made a difference.
For example, an acoustic camera might identify that most of the noise from an industrial machine is coming from a particular panel or component. A more targeted acoustic measurement can then help quantify the resulting noise and support the next stage of the investigation.
Which One Do You Need?
There is no single answer for every noise problem. The right approach depends on what you are trying to establish.
| Your main question | Investigation to consider |
|---|---|
| How loud is the noise at a particular location? | Noise measurement |
| Does the noise comply with an applicable limit? | Professional noise measurement |
| How does noise vary during the day or night? | Longer-term noise measurement |
| Which machine is producing the most noise? | Acoustic camera investigation |
| Which part of a machine is causing the problem? | Acoustic camera investigation |
| Where is sound escaping from a structure? | Acoustic camera investigation |
| How well does a wall or floor block sound? | Building acoustic measurement |
| I need to identify and quantify a difficult noise problem | Noise measurement + acoustic camera |
These are general examples rather than fixed rules. The appropriate method depends on the source, location, measurement objective and any applicable technical or regulatory requirements.
What If You Are Not Sure?
You do not need to know whether you need an acoustic camera or a sound level meter before contacting an acoustic specialist.
Simply explain what you are experiencing, where the noise occurs and what you are trying to find out. For example, you might know that a ventilation system is too noisy but not know which part of the system is responsible. In another case, you may already know the source but need to establish the noise level at a nearby property.
From this information, the appropriate investigation can be determined. Sometimes a standard noise measurement is all that is needed, while more complicated problems may benefit from an acoustic camera or a combination of measurement methods.
Need a Noise Measurement or Acoustic Camera Investigation in Latvia?
NoiseHunters provides professional noise measurement and acoustic camera investigation services throughout Latvia. Our specialists can help assess environmental noise, equipment noise, building-related noise and difficult noise-source problems using the appropriate acoustic measurement technology.
If you need to establish how loud the noise is, our noise measurement service can provide objective acoustic data for the relevant location and measurement conditions. If you need to determine where the noise is coming from, an acoustic camera investigation can help visualise and locate the dominant sound sources.
If you are not sure which service you need, just contact us. Tell us what the problem is, where it occurs and what you are trying to find out. We can discuss the situation with you and recommend the most appropriate approach.
Disclaimer: The choice of acoustic equipment and measurement method depends on the purpose of the investigation, the characteristics of the noise source, measurement conditions and applicable standards or regulatory requirements. An acoustic camera is not automatically a substitute for a formal regulatory noise measurement, and a sound level meter does not necessarily identify the source of a noise. This article provides general information and is not a substitute for a project-specific acoustic assessment.