Facts About Sound

High Frequency Sound

Is greatly reduced by passing through air

More disturbing to the human ear than low frequencies

Strongly directional and more easily reflected

Travels around objects and through openings

Less disturbing to the human ear than high frequencies

Travels further than high frequency

Sound travels at:

1128.6 ft per second in Air

4921.2 ft per second in Water

16404 ft per second in Steel

The average audible frequency range of the human ear is between 20 Hz and 20,000 Hz

The boundary between high frequency and low frequency is 1000 Hz

Loudness is perceived to be doubled if loudness is intensified by 10 dB

The smallest amount of sound level change that is noticed by the human ear is about 2 or 3 dB

Sound travelling through air is reduced by about 6 dB for each doubling of distance

Vibration can provide sound after traveling great distances

More noise is produced from larger vibrating surfaces

Sound level can be increased if the sound source is placed in a corner

Large quantities of mass and or high density type products have good noise barrier characteristics (e.g: concrete, lead, barium loaded PVC)

To increase sound transmission loss: incorporate a space between the barrier layers

Dampened surfaces dissipate vibration more quickly and therefore produce less noise

By shifting resonance to a higher frequency it is more easily dampened

A machine with excessive vibration can be damped by either mounting it to high density mass or on properly designed isolator mounts

Learn more about Acoustics and FabriTRAK® Specifications.