How loud?

[MORELLO]

How loud, ie. any recogniseable equivalent, is 139 decibals?

[MORELLO]

Threshold of pain. I like it...

Thanks Zacsmaster.

[jake-the-peg]

Read that link carefully decibels are a log scale so 139 is *A LOT* louder that 130

Note 140 is the sound of a formula 1 engine at the range of 1 meter 150 is a jet engine and 180 was Kratakoa at 1 mile!

[jake-the-peg]

Oh BTW 8 hours exposure to 90db will start to cause damage and hearing loss.

140db causes immediate< damage

[Stevee]

Jake Did the people on Jave ask for them to turn it down :-)

[ainitatyb]

Note also that damage to hearing is irreversable, it will not become better in time.

[kwicky]

I may be wrong but I believe our hearing mechanism in the inner ear calibrates the sound in decibels and is not a straight line sound receiver?

[tubeway]

How the sound is heard also depends on the frequency (pitch) of a note - that is why audiologists (like myself) - use a weighted scale which is notated as dBHL (decibel hearing loss) as opposed to the unweighted dBSPL (decibel sound pressure level) scale. When measuring noise - then other weighted scales are used, most commonly dB (A), although very loud sound may use other scales such as the dB (D) scale.
The dBHL scale was devised by the National Acoustical Laboratories in Australia after extensive testing of the hearing thresholds of young adults.

[kwicky]

Yes I suppose that the frequency range of human hearing is between 20 to 20,000 hz

[tubeway]

That is true - but as we get older we loose yhe ability to hear in the higher frequencies. I see many (older) people where the hearing threshold is in excess of 80 dBHL at 8kHz

[jpms1]

Most gp race bikes give off around 102 -110 decibals at 6,000rpm.And as you can imagine this is loud.Most attract the police's attention when these exhaust type systems are used on the public roads.Some of the uk race circuits have a noise limit in place to stop the locals taking legal action over the noise.So your 139 decibals could give people heart attacks or start a fit if the person was not ready for it.

[jpms1]

btw.at the track we wear ear plugs and can still feel the noise effecting the heart's rhythm.Sort of feeling you get if you've been to an air show and the fighter jet engine points your way.A pounding type.