Effective noise control systems require a basic understanding of the science of acoustics and sound. Singer Safety Company understands the science behind noise control systems, how noise travels, and how to reduce the impact of excessive noise. Noise control methods, including sound absorption, isolation, and vibration dampening, work together to lessen exposure and risks associated with noise.
What is Noise?
In order to understand the science behind noise control systems, we need to understand the basic science of sound. Sound and noise are the same thing, at least according to science. However, “noise” is generally used specifically to describe unwanted, annoying, or excessive sounds. All noises are sounds, but not all sounds are noise.
Sound is a type of energy created through vibrations in the air (or in water, metal, or occasionally other mediums). The vibrations cause waves of pressure, known as sound waves. Sound is measured by frequency and amplitude.
Sound frequency is the number of vibrations per second, measured in Hertz (Hz). Higher frequencies produce higher-pitch sounds, and lower frequencies produce lower pitches. Amplitude determines how loud a sound is. The height of the sound wave, the stronger the vibrations, the louder the sound.
Sound intensity is universally measured in decibels. Decibels are a logarithmic scale, compressing the entire range of human hearing into manageable numbers. The average human ear can detect sounds ranging from 0 dB to around 120-140 dB, which is the threshold for pain and immediate damage to the ears. We don’t need to understand the equations and calculations that determine decibels in order to grasp the scale. Normal conversation is around 60 dB, power tools and machinery range from around 90 dB to 120 dB, and a jet engine taking off is around 150 dB. It’s important to remember that these measurements are generally from standing right next to the source of the noise.
Prolonged or repeated exposure to noises over 85 dB can cause hearing loss, and exposure to sounds as loud as 140 dB can cause immediate hearing damage and pain. The risk of excessive noise exposure in daily life, especially in specific work environments, is why noise control technology is critical. The science behind noise control systems limits the risk to employees and customers and protects everyone’s hearing.
Noise Control Methods
The science behind noise control systems breaks down to noise absorption vs. noise isolation and vibration dampening. Different types of noise control technology rely on these methods to reduce the overall impact of noise.
Sound Absorption
Sound absorption methods focus on trapping sound waves. Acoustic materials such as foam, fiberglass, and acoustic panels have an open-cell structure that allows sound waves to enter and get trapped. Sound absorption and acoustic materials are especially useful in any space where acoustics and reducing any echo are essential.
Singer Safety’s noise control technology aims to absorb sound, and it includes our acoustic foam and ceiling baffles.
Acoustic foam is an incredibly versatile acoustic material that can be installed on walls or doors, lining machine or equipment surfaces, or nearly anywhere else where sound absorption is beneficial. The open, flexible structure of foam acts as a natural sound wave-absorbing material. Singer Safety offers standard acoustic foam, aluminized mylar foam, and convoluted foam.
Ceiling baffles hang from ceilings, generally in large open spaces such as warehouses or gyms. They absorb sound waves that bounce around in a large space. They work to reduce any amplified sounds. Our ceiling baffles are made with quilted fiberglass materials or poly-covered fiberglass.
Noise Isolation
Noise isolation methods rely on barriers to prevent sound from passing from one space to another. Permanent noise isolation techniques include walls made from dense, heavy materials such as concrete. Temporary or versatile isolation barriers include acoustic screens. Screens can be placed around noisy machinery to isolate the sounds.
Modular acoustic screens are versatile sound barriers that can isolate noise and prevent sound waves from traveling. Singer Safety’s screens can be easily moved or joined, offering flexibility and easy adaption to any environment.
Quilted fiberglass panels, or QFP, are sound barriers made from fiberglass material. They are lightweight and semi-flexible and best used as a suspended barrier. Our fiberglass panels combine high-quality noise absorption, noise barrier, and noise-canceling power for machinery, walls, and doors.
Vibration Dampening
Since all noise is vibrations, dampening those vibrations will reduce excessive noise. Materials such as rubber and viscoelastic compounds and other materials that absorb and dissipate vibrations. Dampening materials are often installed in or around machinery, appliances, and even vehicles.
Singer Safety’s vibration-dampening compound stops vibration-induced noise at its source. The compound is easily installed in an infinite number of applications. The paste can be brushed, sprayed, or troweled on a variety of surfaces.
Types of Controls
Noise control technology and noise absorption vs. noise isolation are just one type of noise control method. The science behind noise control systems extends beyond acoustic materials. Passive noise control, active noise control, engineering, and administrative controls all work together to create the safest possible environments.
Engineering controls are any adjustments that involve physical changes to the environment. This includes modifying, upgrading, maintaining, and replacing machines or equipment. Passive noise controls are a type of engineering control that includes using any noise control technology and acoustic materials to absorb, dampen, and isolate noise.
Installing a noise control system is not the only way to ensure noise levels are within compliance. Administrative controls work to limit exposure to noise. Rearranging schedules and facility layouts and providing training and education are all examples of administrative noise controls.
Active noise control is generally known as noise cancellation. This uses the science behind noise control systems to cancel out unwanted noise with different sound waves.
Microphones can detect the incoming unwanted noise and then create “anti-noise” sound waves in the exact opposite degree to cancel out the noise. This type of noise control is most common in noise-cancelling headphones.
Ideally, noise exposure is limited at the source. The use of personal protective equipment, or PPE, should only be necessary if other noise control options are not enough.
Singer Saftey Company
Singer Safety Company is an expert in the science behind noise control systems. Our expert team understands how different noise control technologies work together to create the most efficient noise reduction system and protect all employees from the harm of excessive noise exposure.