Filter or modify an in-air sound to make it sound how it would underwater?

Question

I have recordings of a particular sound generated by a fishing vessel. Our team is trying to identify what exactly ON the fishing vessel is the source of that sound we as of yet only have underwater recordings of. So, we have gone around and collected recordings at different pieces of equipment on the deck of the fishing vessel to compare.

So far, we haven't been able to match anything up, but my ear is trained for the specific sound as it is recorded underwater, from several km from the vessel, not just a few meters from the equipment in air.

Is there a way to modify/filter/manipulate a sound recording in some way to "mimic" the sound propagating through water instead of through air to make it a bit clearer to compare the recordings?

Answer 1

Do not know of any specific method - and I'm probably very off here. I'd approach the problem with a custom-built finite-impulse response (FIR). The filter is (very broadly speaking) generated by comparing a known recording of the sound with the sound recorded in the space of interest.

The FIR is the method that allows you to recreate the way a song may sound if played in a small room or in a cathedral.

No idea what all goes into making an underwater FIR, but it may perhaps get you close? I'm guessing making the filter will involve playing back known sounds in air and in water.

For more reading on FIRs, this classic reference may be of use.