whale sounds?

[Hunt Stoddard]

I live in Keaukaha, past the port and about three or four hundred feet from the ocean. I now realize that for a few years around this time I've been hearing this weird sound, like someone blowing into a didgeridoo but not knowing how to play it, and I'm wondering if this is the whales? It's a really odd, high pitched sound, usually late at night, like someone running a ruler rapidly back and forth on a cloth sheet.