Hey, thanks!
I have actually wondered about the name thing. It is a little whimsical, and I guess it would be easy to mix up with lots of similar descriptions like "a quiet buzz" or "a gentle burble". From that perspective, it might have been better to choose something more memorable.
The site won't rank well in google for descriptive terms because it doesn't contain a lot of text. Even for terms it does contain, it doesn't do very well (e.g. it ranks at ~20 for "ambient noise" in google US). I haven't worried about that so far because the large majority of the traffic is direct, social or for the exact term "a soft murmur".