It is a good question - I suspect that the sound of a breaking wave arises from the bubbles made by the impact 'ringing' - the fundamental mode of which will vary with T and the ratio of specific heats (gamma).

So I'd expect breaking waves on Titan to have fewer large bubbles (weaker gravity) but on the other hand the syrface tension of N2/ethane is lower than that of water, so might not bubbles be larger?

Either way, the speed of sound is 2/3 that of that at Earth's sea level - so a vibrating bubble ought to have a lower tone - if bubble sizes are like those on Earth, then the speed of sound alone will make crashing breakers sound deeper in pitch.

I think.

-fun!-