Noise as a Competitive Factor –
How to Win with Acoustic Cameras!

Why is machine noise suddenly becoming a competitive factor?

The new regulation forces manufacturers to disclose their machine noise levels. This means: The quieter the machine, the more attractive it is to customers.

1. Noise reduction reduces operating costs for customers

Less machine noise means less expenditure on soundproofing measures , such as hearing protection, noise-protection booths, or insulation materials. Companies that want to invest in quieter production will prefer to purchase machines with optimized noise levels.

2. Ergonomic machines are preferred

High noise levels stress employees and can cause long-term health problems. Companies that prioritize employee health and occupational safety will prefer machines with low emissions.

3. Manufacturers with lower noise levels have a marketing advantage

Since buyers can now directly compare noise levels, manufacturers can actively advertise quieter machines – for example with labels such as “Silent Mode” or “Low-Noise Technology”.

What is an Acoustic Camera?

An acoustic camera combines advanced microphone arrays with visual technologies to make noise sources visible. It generates acoustic heatmaps that accurately depict the position and intensity of noise sources, enabling quick analysis.

The Seven Bel Sound Scanner is the first acoustic camera based on the Sound Field Scanning principle. It locates sound sources within a frequency range of 125Hz to 44kHz, providing high-resolution acoustic images directly on a mobile device for analysis.

Key Benefits of an Acoustic Camera:

1. Precision: Pinpoint location of noise sources by visual representation of hotspots. Even complex noise issues can be efficiently analyzed and resolved.
2. Efficiency: Rapid data collection and automated analysis save time and reduce costs compared to manual measurements using single microphones or accelerometers.
3. Flexibility: Suitable for a wide range of applications—from small components to large machinery, from cabin measurements to outdoor noise mapping around the machine. Its mobility allowss flexible adaptation to different requirements.

Applications for Machine Tools

1. Optimization of Milling Processes

When machining parts with milling tools, the feed rate and speed of the milling cutter can induce resonances in the machine or the part. These vibrations can lead to unwanted noise emissions, poor surface quality, and increased tool wear.
Challenge:
It is crucial for engineers to precisely identify where and why these resonances occur. Conventional vibration and noise analysis methods often provide only point-based or indirect measurements, making it difficult and time-consuming to determine the exact source and location of the sound emission.
Solution:
An acoustic camera can be used to visually display the noise sources during milling. Engineers can precisely identify the locations of the machine or part where critical noise is generated. This enables targeted optimization – whether through mechanical adjustments, changes to milling parameters, or measures to dampen resonances. The rapid, visual analysis helps to efficiently identify sources of error and sustainably improve process quality.

Example:
During edge grinding on glass panels of known dimensions, peaks in the sound pressure level are detected at specific points along the edge. The acoustic camera isolates the time and frequencies at which this resonance occurs and localizes the dominant sound emission at the right end of the glass panel. Due to the selected speed, the harmonic force applied by the milling cutter excites a resonance frequency and associated vibration mode of the glass panel. Engineers can thus immediately recognize that this is not a design problem with the machine. This resonance frequency can be avoided by adjusting the grinding speed.

2. Commissioning of Machines

High noise levels at the workplace of a machine tool can impair the health of machine operators and require an occupational health and safety assessment. Increased noise exposure can be caused by the machine itself as well as by room acoustic effects due to its location in the production hall. Without a precise analysis, it often remains unclear which measures can effectively reduce noise.
Challenge:
It is crucial for manufacturers and operators to determine precisely where and why noise emissions occur. Conventional noise measurements provide values ​​but lack detailed spatial mapping of the noise sources. This makes it difficult to implement targeted improvements to the machine or its surroundings.
Solution:
The acoustic camera enables precise visualization of sound sources during the machining process at the machine operator’s location. This makes it possible to clearly identify whether the noise is caused by the machine itself (e.g., inadequate enclosure, acoustic leaks, loose attachments, defective components) or by unfavorable room acoustic conditions (reflections from ceilings and walls). This information can be used to implement targeted measures such as additional enclosure panels with absorbent materials or room acoustic optimization (e.g., ceiling or wall absorbers). This leads to a sustainable reduction in noise exposure and significantly improves occupational safety.

Example:
The sound pressure level at the operator’s location needs to be reduced during an acoustically intense machining process (drilling through holes in a cylinder block). The acoustic camera shows the dominant sound source not at the machine, but as a reflection on the glass facade of the production hall. The reason for this sound propagation is an opening on top of the machine, necessary for thermal reasons. Sound from the machining process escapes at this point and is reflected through the glass facade to the measurement point. In this case, room acoustic measures in the form of wall absorbers are the most effective way to reduce the sound pressure level.

3. Acoustic Leaks in the Enclosure

High noise levels can not only impair operator comfort, but also jeopardize their concentration and safety. Acoustic cameras can identify leaks and weak points in the enclosures of machine tools that cause unwanted noise to propagate from inside to the work environment outside. Targeted soundproofing measures or checking manufacturing tolerances can significantly improve the work environment and reduce operator fatigue.

Challenge:
Conventional methods of leak testing using a tracer gas require considerable time and have numerous limitations, such as the lack of quantifiability of leak rates, the requirement of controlled conditions with low external air movements and the deposition of the tracer gas in the interior.
Solution:
In combination with an ultrasonic loudspeaker inside the enclosure that emits inaudible, high-frequency sounds, an acoustic camera can quickly and efficiently identify the locations where the high-frequency sound penetrates the enclosure.

Example:
During commissioning of a machine tool, the tightness of the enclosure is tested. A dominant leak is located at the lower part of the door. The seal is inspected and reworked at the relevant locations. The test is repeated until the acoustic limit defined for the machine type is passed.

Learn More in our Webinar

An acoustic camera is a modern and effective tool for tackling complex challenges in the development, maintenance, and manufacturing of construction equipment. It not only helps reduce noise exposure for machine operators but also assists in troubleshooting to ensure compliance with legal regulations.

Your next step: Sign up for our webinar and discover how the acoustic camera can revolutionize your daily work as a development engineer, production technician, or service technician!

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