08-14-2014, 10:03 AM
Acoustical Terms
Sound: a vibration or wave motion that can be heard, reaches the ear through air, the air vibrates back and forth in tiny molecular motions of high and low pressure
Decibel: the unit of measurement used to indicate the loudness or intensity of sound; comparable to the “degree” as a measurement of heat or cold
Reverberation Sounds: airborne sounds which continue after the actual source has ceased, caused by reflections from floors, walls and ceilings
Frequency: rate at which sound energized air molecules vibrate
Impact Sounds: sounds that are carried through the building by the vibrations of the structural materials themselves
Masking Sounds: normal sounds within habitable rooms which tend to “mask” some of the external sounds entering the room
Decibels Reduction: expression used to indicate the sound insulating properties of a wall or floor panel
Sound Transmission Loss: STL, the number of decibels which sound loses when transmitted through a wall or floor
Sound Absorption: capacity of a material or object to reduce sound waves by absorbing them, these sounds are otherwise reflected and cause excessive reverberation and build up of intensity within that area
Noise Reduction Coefficient: NRC, the sound absorption of acoustical materials is expressed as the average percentage absorption at the four frequencies which are representative of most household noises, these frequencies are 250, 500, 1000, and 2000 cycles/second
Sound Transmission Class: STC, single number which represents the minimum performance of a wall or floor at all frequencies, the higher the STC number, the more efficient the wall or floor will be in reducing sound transmission.
Sound: a vibration or wave motion that can be heard, reaches the ear through air, the air vibrates back and forth in tiny molecular motions of high and low pressure
Decibel: the unit of measurement used to indicate the loudness or intensity of sound; comparable to the “degree” as a measurement of heat or cold
Reverberation Sounds: airborne sounds which continue after the actual source has ceased, caused by reflections from floors, walls and ceilings
Frequency: rate at which sound energized air molecules vibrate
Impact Sounds: sounds that are carried through the building by the vibrations of the structural materials themselves
Masking Sounds: normal sounds within habitable rooms which tend to “mask” some of the external sounds entering the room
Decibels Reduction: expression used to indicate the sound insulating properties of a wall or floor panel
Sound Transmission Loss: STL, the number of decibels which sound loses when transmitted through a wall or floor
Sound Absorption: capacity of a material or object to reduce sound waves by absorbing them, these sounds are otherwise reflected and cause excessive reverberation and build up of intensity within that area
Noise Reduction Coefficient: NRC, the sound absorption of acoustical materials is expressed as the average percentage absorption at the four frequencies which are representative of most household noises, these frequencies are 250, 500, 1000, and 2000 cycles/second
Sound Transmission Class: STC, single number which represents the minimum performance of a wall or floor at all frequencies, the higher the STC number, the more efficient the wall or floor will be in reducing sound transmission.