Available Modules

Engine Drive Systems: Considerations with Engine Applications - Sound Attenuation

Exhaust Silencers
Engine exhaust noise is controlled through the use of silencers and mufflers. Generally, there is no technical distinction between a silencer and muffler and the terms are frequently used interchangeably. A silencer has been the traditional name for noise attenuation devices, while a muffler is a smaller, mass-produced device to reduce engine exhaust noise.

The use of an exhaust silencer is prompted by the need to reduce the engine exhaust noise. In most applications the final selection of an exhaust silencer is based on a compromise between the predicted acoustical, aerodynamic and structural performance in conjunction with the cost of the resulting system.

Silencer Types
Despite terms and various configurations, the silencer can be broken into three fundamental types: reactive, absorptive and combination reactive/absorptive. In addition to the three main silencer types, other functionality such as spark arresting, emission control, and heat recovery may also be incorporated into the silencer design. Each type of silencer has specific performance attributes that can be used independently or in combination to produce the required insertion loss (IL) for a specific application.

Sound Enclosures
Sound attenuation enclosures are also available or can be manufactured for indoor and outdoor installations for most engine driven equipment.

Sound Absorbing Material
Sound absorbing material is designed to be applied on engine enclosures or walls and ceilings. Sound stop materials will reduce noise levels by minimizing noise reverberation.