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marketrent OP t1_j98sh5l wrote

Reply to comment by websterhamster in ‘We found the Artemis-I noise level at 5 km had a crackling quality about 40 million times greater than a bowl of Rice Krispies.’ — Maximum noise measured during Artemis-I launch on 16 Nov. 2022 was higher than predicted by marketrent

From the linked release:^1

>At 1.5 km from the pad, the maximum noise level reached 136 decibels. At a 5.2 km distance, the noise was 129 decibels, nearly 20 decibels higher than predicted by a prelaunch noise model.

^1 The Roar and Crackle of Artemis 1, AIP Publishing, 14 Feb. 2023, https://publishing.aip.org/publications/latest-content/the-roar-and-crackle-of-artemis-1/

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RollinThundaga t1_j990ccl wrote

For general reference; a 10 decibal increase in sound intensity is an apparent doubling of the loudness.

130 decibels is the human pain threshold. A lawn mower is around 90 decibels. A normal conversation is about 60 decibels.

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marimbawarrior t1_j9b6arb wrote

Key word: apparent. Actual doubling of sound pressure levels is every 3dB. Every 10dB added is 10x the energy. (Sound energy and volume are two different things but they’re directly proportional)

Honestly surprised that it’s only 136 dB around the rocket. Also surprised that they didn’t also state the C-weight, as that would highlight more of the low end you get from the rocket itself. There’s a ton of low end that’s being tossed out (for good reason) when they A-weight.

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mmgoodly t1_j9dkgev wrote

No bone to pick with most of what you wrote... but

> around the rocket

1.5 kilometers from the rocket.

IMMEDIATELY around the rocket (which is what I'd mean if I said simply "around the rocket") would be a different story. Obvs.

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marimbawarrior t1_j9dtbw4 wrote

True! Inverse square law can help us out here.

Just punched the numbers in, 26 dB louder if you were located 80 meters away from the rocket, or roughly 162 dB. So yeah, 136 dB from 1.6 km would make total sense.

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