Acoustic Cameras: Your Solution for Quieter Construction Equipment and Maximum Operator Comfort

Legal Requirements and Customer Expectations

Modern construction machinery is powerful, efficient, and indispensable for large infrastructure projects. However, its power is often accompanied by significant noise emissions—whether from engines, transmissions, or cooling systems. Noise not only affects operator comfort and safety but also has implications for environmental regulations and legal compliance.

This is where the innovative acoustic camera technology comes into play: It enables precise localization and analysis of noise sources, helping to make machines quieter, more efficient, and more durable.

This article explains how an acoustic camera works, its advantages, and how it can be used in the development, manufacturing, and maintenance of construction equipment.

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:

Precision: Pinpoint location of noise sources by visual representation of hotspots. Even complex noise issues can be efficiently analyzed and resolved.
Efficiency: Rapid data collection and automated analysis save time and reduce costs compared to manual measurements using single microphones or accelerometers.
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 in the Construction Equipment Industry

1. Compliance with Legal Noise Requirements

Many countries and regions have strict noise protection laws that affect both machine manufacturers and operators. Especially during product testing and certification processes, machines must comply with specified noise limits. Acoustic cameras enable detailed and precise localization of noise sources in engines, transmissions, or cooling systems. This helps engineers make targeted improvements to meet legal requirements without compromising machine performance.

Challenge:
Measurements according to ISO 3744 to verify compliance with the requirements of Directive 2000/14/EC only indicate whether the limits in the form of maximum permissible sound power levels are met or not. However, they do not clarify whether a violation is due to product design, defective components, or manufacturing tolerances.

Solution:
Acoustic cameras identify key noise sources in a machine. Combined with an understanding of the machine’s design and manufacturing process, engineers as well as service and production technicians can quickly and effectively determine the cause of excessive noise levels and implement high-quality technical solutions.

Example:

During acoustic comparative measurements on prototypes of a wheeled excavator, differences in the sound power level of 4 dB were detected. Quick measurements around the vehicle identified the rear section as the problematic area. The cause was found to be a leak in the engine cover near the exhaust system.

2. Reduction of Cabin Noise

A high noise level in the operator cabin can not only reduce operator comfort but also impair concentration and safety. Acoustic cameras can identify leaks and weak points in the cabin structure that allow unwanted noise to enter from the outside. Through targeted sound insulation measures and the inspection of manufacturing tolerances, the working environment can be significantly improved, reducing operator fatigue.

Challenge:
Traditional methods of leak testing using smoke require significant time for preparation and have various limitations, such as the inability to quantify leak rates, the necessity of controlled conditions with minimal external airflow, and the deposition of smoke residues inside the cabin.

Solution:
In combination with an ultrasonic speaker inside the cabin that emits inaudible high-frequency tones, an acoustic camera can quickly and effectively identify the locations where the high-frequency sound passes through the insulation.

Example:

As part of the maintenance work on a cabin door, the sealing is tested. A major leak is identified at the lower part of the door, while a minor leak is detected at the upper part. The insulation is inspected and reworked accordingly. The test is repeated until the predefined acoustic threshold for the construction is met.

3. Noise and Vibration Analysis

In addition to complying with noise limits and optimizing operator comfort, NVH comfort (Noise, Vibration, Harshness) plays a crucial role in vehicle performance. Unwanted noises such as buzz, squeak or rattle sounds (BSR) may indicate design flaws, manufacturing defects, or material fatigue. Acoustic cameras enable a precise analysis of these noises both inside and outside the machine. This allows for early detection and resolution of issues before they lead to costly repairs or quality degradation.

Challenge:
In modern construction equipment, numerous components are packed into a confined space, creating multiple potential sources of noticeable noise. Acoustic reflections and structure-borne sound transmission can mislead the human ear about the actual origin of a sound, making human noise localization virtually impossible.

Solution:
Acoustic cameras enable precise localization of unwanted noises even in a challenging acoustic environment. The noise can not only be pinpointed but also filtered by frequency, allowing the measurement results to be aligned with the subjective auditory perception.

Example:

A squeaking noise in the engine compartment of a construction machine can be pinpointed to a pulley of the V-belt. This eliminates the need for a lengthy trial-and-error process, allowing for a targeted component replacement that resolves the issue immediately.

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!