I agree with the other commenter, doesn't really seem to matter in this setting.
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".
Pedantic nitpick: it's not nonsense if the common person understands the meaning. Your average english speaker uses "decibels" to mean "dBSPL" since most people aren't aware of the other ones.
It's still nonsense and devoid of meaning, and the nonsense has nothing to do with the unit presented or any simplification of that unit.
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.
SkyPuncher|2 years ago
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".
huimang|2 years ago
ssl-3|2 years ago
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.
ktm5j|2 years ago