One of world’s smallest fish found to make sound as loud as a gunshot
theguardian.com
theguardian.com
- Sound levels are usually assumed to be measured 1m away. For the fish, it’s measured one body length away (inverse square law applies)
- Jet engines are often measured from many meters away (again inverse square law)
- The fish’s sound is pulsed and lasts only 2.5ms, while jet engine noise is continuous.
- The frequency emitted by the fish “exceeds 20kHz”. The frequency range of a jet engine spans almost the entire range of human hearing.
- Standing next to one might startle you a bit, the other will irreversibly damage you.
The article compares it to a sledgehammer, ambulance siren or a gunshot. A gunshot of which is not a continuous sound.
Regardless, it is impressive that a 12mm fish can produce such a loud sound regardless of whether it is continuous and/or throughout our frequency range of hearing.
140dB at 12mm is equivalent to 100db at 1000mm. So that's 20dB less than an "ambulance" or "jackhammer" as listed here[0]. Which definitely would make the article misleading.
0: https://noiseawareness.org/info-center/common-noise-levels/
Months later when I drained the tank to move into a new house, and removed all the live rock I found it dead at the bottom. Amazing that such a tiny thing can make so much noise.
Mantis shrimp are exotic terrors of the deep you don't exactly forget you have.
You usually have to special-order mantis shrimp. It's easy to accidentally get a pistol shrimp when you asked for a peppermint; they look similar.
Yep. Any fish you put in the tank would disappear soon after.
Sound pressure level measurements relate to the pressure at a point in space, and do not relate -- by themselves -- to the total sound energy being produced by a thing.
I can make an SPL measurement, in air, that is ~6dB higher or lower by halving or doubling (respectively) the distance betwixt the thing making the sound and the thing measuring the sound.
If a sound measures 100dB at a distance of 2 meters, then the same sound also measures 106dB at a distance of 1 meter, or 112dB at 0.5 meters, or 118dB at 0.25 meters.
A difference of 18dB is a difference of nearly two orders of magnitude.
The study says this fish made a sound at a level of 140dB at a measurement distance of one fish length of 12mm, in water.
To compare a 140dB fish-noise that to a the SPL of a gunshot, we'd first need to measure a gunshot -- in water -- at a distance of 12mm (or extrapolate for a larger distance).
And I have certainly not done this measurement myself, but I strongly suspect that the intensity of the gunshot will blow the noise of this fish out of the water in an an apples-to-apples comparison.
Colloquially, "decibel" is a widely known scale ranging from "I can barely hear that" to "holy crap, that's loud". 140 decibels communicates this fish is capable of a surprisingly loud sound - which is surprising. I don't really care if it's entirely accurate. I simply know that it's "surprisingly loud".