If you own or operate a factory, manufacturing plant, or other industrial facility, it’s important to keep noise levels under control. Otherwise, it can impact the health of workers and productivity in the long run.
Industrial noises can vary significantly by location and time of day, but they can all be reduced with the use of sound enclosures. This helps ensure compliance with OSHA regulations and limits noise disturbances outside the premises.
Active Noise Cancellation
Active Noise Cancellation is a type of noise control that can be used in industrial environments to reduce outside noise. Developed as a technology for airline pilots in the 1950s, ANC works to pick up ambient sounds and then invert them.
This reversed sound then combines with the ambient sound to cancel it out. It can cut mid- to high-frequency noises by about 15dB, while low-frequency sounds can be canceled out by as much as 60dB.
There are several types of ANC systems and each one has its own strengths and weaknesses. The simplest is feedforward ANC, which uses a noise-capturing microphone that’s positioned outside the headphones.
The other type is feedback ANC, which has a microphone set inside the headphones. This type is more sensitive to low-frequency noises and can isolate certain sounds, such as traffic. However, it can be less effective when capturing unpredictable sounds like wind howl. And it may cause ringing in poorly designed headphones.
Passive Noise Cancellation
Passive Noise Cancellation is a relatively low-tech method of noise control. It works by forming a physical barrier around the ears to block out ambient sound.
In general, passive noise cancellation is not as effective at blocking out high-frequency sounds as active noise canceling (ANC). However, it is more effective at drowning out low-frequency sound.
When a microphone in a noise-canceling headset detects external sounds, it sends an inverse of the sound wave it’s listening to. This inverse has the same amplitude as the original sound, but is 180 degrees out of phase.
When these two sounds collide, they cancel out each other, effectively erasing the sound waves from the outside world before it reaches your ear. This type of noise-canceling technology is used in a variety of products, including headphones and earbuds.
Constrained Layer Damping
Constrained Layer Damping (CLD) is a popular vibration control technique that dissipates vibration energy. This is achieved by placing a high damping material between two metal sheets to create a laminated sound deadened panel.
Constrained layer damping is 30% more effective than traditional damping techniques because it prevents the damping material from deforming as the panel vibrates. It also avoids hygiene, wear and “peeling” problems that are common with stick-on damping.
Using COMSOL, a modeling and optimization method was developed to determine the optimal thickness of viscoelastic material (VEM) and constraining layers for CLD structures. The results show that the loss factors of VEM and constraining layers increase as a function of the thickness of the VEM and constraining layers, and are primarily determined by shear.
Constrained layer damping is a highly effective vibration control treatment that can be used in many applications. It is a very simple damping technique that can be implemented quickly and inexpensively.
Noise-canceling headphones can be very useful in industrial noise control. They use an active technique to reduce unwanted sounds by utilizing a microphone to detect noise and create an opposite signal to play into the ear.
This is a very important function, as it can allow workers to concentrate on tasks without being distracted by what’s going on around them. It can also help team members understand each other’s communication more clearly, which can make it easier for teams to work together and get things done.
This type of noise reduction is a more effective technique than passive noise isolation because it uses a heavy-duty design to effectively seal the ears and drown out sound. It’s a great choice for noisy environments such as construction sites or loud airports, as it can protect hearing from explosive transient sounds and high-frequency sounds.