Mike Wilson's Blog

I was a MA/MST student at Stanford's Center for Computer Research in Music and Accoustics.

This is my weblog.

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2010-10-08

We went whale watching in Monteray.  Well, more like whale listening.
MA/MST Chris took a picture of me:



We made hydrophones earlier in the quarter out of a piezoelectric disc
sealed between two pieces of Plexiglas by a toilet gasket and some
epoxy putty.  We got a chance to test them out on a whale watching
boat.

There was one blue whale and there were also two humpback whales.  But
I didn't see them.  I did see several sea lions, birds, seals, an
otter, and a few dolphins!

Listening with the hydrophone was interesting.  There are shrimp in
this area that make an extremely loud noise by shooting water through
their claws, causing cavitation in the water.  It sounds a bit like
popcorn.  I could also hear engine noises, and water noises.  There is
also a satisfying "plop" when the hydrophone enters the water.  I
couldn't identify any other animals.

We also blew a tube in the water, and hung a cymbal over the side of
the boat and struck it.  Both were very audible.  Sound travels five
times faster in water than in air, but frequencies are transmitted
differently.  The cymbal sounded different in water than in air, but
that may also have been due to the headphones I was listening through.

Unfortunately the best listening session I had I didn't seem to record
properly.  I may have made an error operating the handheld recorder.
This was my first time using it.  Even so, I still got a few minutes
of shrimp and water noises.