I have been thinking about underwater sounds (i.e. sounds produced and recorded underwater), what exactly the water does, and how to emulate this effect. Imagine a sound played underwater (e.g. from speakers or from a dolphin) and being recorded underwater by a hydrophone. Imagine that it is in a very large basin (e.g. the sea) which doesn't produce any sound of it's own (this would not be very realistic for the sea I admit). What I would like to know is the frequency response of this medium.
Intuitively, I would say that water has a low-pass filtering effect: as the viscosity of water is much higher than in air, I think that high frequencies are attenuated more than low frequencies. But that doesn't feel quite right: when I think about when you're underwater, it feels like high frequencies are very pronounced, and sounds have a bit of a 'ring' to them.
In other words, I can't quite figure it out on a theoretical basis. I have tried to find underwater impulse responses and proper underwater recordings, but I can't find a satisfying recording. Let alone a frequency response for water. Can someone help me in this?