Type Of Noise

 

Sonic-Shield outlines different types of noise.

  • Airborne noise passes through openings, apertures and other structural gaps.

  • Ambient Noise: background noise that naturally occurs in your home.

  • Flanking noise: The ability of sound to find the path of least resistance, passing around heavy, insulated areas into the adjacent rooms. When blocking sound, it is more like water than light – if there are any holes, the water will continue to flow until it has passed through the most easily. Sound does the same thing! 

  • Impact noise: The sound produced by the collision of two solid objects. Typical sources are footsteps, dropped objects, etc. on an interior surface (wall, floor, ceiling) of a building. 

  • Impulsive noise: A) Either a single sound pressure peak (with either a rise time less than 200 milliseconds or total duration less than 200 milliseconds) or multiple sound pressure peaks (with either rise time less than 200 milliseconds or total duration less than 200 milliseconds) spaced at least by 200 millisecond pauses, B) A sharp sound pressure peak occurring in a short interval of time.

  • Masking noise: A noise that is intense enough to render inaudible or unintelligible another sound that is also present.

  • Pink Noise: Noise with constant energy per octave band width.

  • Random Noise: An oscillation whose instantaneous magnitude is not specified for any given instant of time. It can be described statistically by probability distribution functions giving the traction of the total time that the magnitude of the noise lies within a specified range.

  • Structural borne noise: created by impact or by vibration.

  • White noise: Noise with energy is uniform over wide range of frequencies, being analogous in spectrum characteristics to white light.

  • Ultrasonic sound: Is sound above the audible range of human hearing this is usually above 20,000HZ Some animals like dolphins and bats communicate above this frequency. Much higher frequencies are used for medical ultrasound.

  • Infrasound: is sound below the audible range of human hearing or  20Hz or below. Many times this type of sound can affect humans as a vibration when the sound pressure is extremely high. 

Other types of noise can be defined by the noise source itself such as marine noise, automobile noise, airport noise, machine noise and so on. The sources of noise are so numerous and varied that we have decided to stick to the types of noise defined above as they are the most commonly used terms when analyzing a noise problem and developing a solution.