Transmission loss
Sound measurements | |
---|---|
Characteristic |
Symbols |
Sound pressure | p, SPL |
Particle velocity | v, SVL |
Particle displacement | δ |
Sound intensity | I, SIL |
Sound power | P, SWL |
Sound energy | W |
Sound energy density | w |
Sound exposure | E, SEL |
Acoustic impedance | Z |
Speed of sound | c |
Audio frequency | AF |
Transmission loss | TL |
| |
Transmission loss (TL) in general describes the accumulated decrease in intensity of a waveform energy as a wave propagates outwards from a source, or as it propagates through a certain area or through a certain type of structure.
It is a terminology frequently used in optics and acoustics. Measures of TL are very important in the industry of acoustic devices such as mufflers and sonars.
Measurement
Measurement of transmission loss can be in terms of decibels.
Mathematically, transmission loss is measured in dB scale and in general it can be defined using the following formula:
where:
- is the power of incident wave coming towards a defined area (or structure);
- is the power of transmitted wave going away from the defined area (or structure).
Transmission loss may refer to a more specific concept in one of the field below.
Duct Acoustics
- Transmission Loss (duct acoustics) in duct acoustics describes the acoustic performances of a muffler like system.
Room Acoustics
- Transmission Loss in room acoustics describes the decrease of sound intensity that is reduced by a wall or other structure at a given frequency.
Underwater Acoustics
- Propagation loss (sometimes referred to as transmission loss) is a quantitative measure of the reduction in sound intensity between two points, normally the sound source and a distant receiver.
References
This article is issued from Wikipedia - version of the 8/30/2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.