This is forwarded from Robert Yourell,
Please include Mr. Yourell in your reply since he's not on Bioacoustics-L.
---------------------------------------------------------------------
Do you know of anyone interested in the production of psychoacoustic illusions
by animals, particularly birds? I would like to know if anyone is familiar the
subject or with what I experienced when I was in Mexico (Chichen Itza).
I heard a bird that could, in a rapid sequence, imitate the sound of a larger
wingspread bird taking off toward me, and of twigs rattling as though a heavy
bird had just launched from a dry branch. I am assuming this is an evolutionary
adaptation to scare away predators of some kind. I know that the effectiveness
of psychoacoustic illusions depends quite a bit on the shape of the listener's
ears, so I'm surprised this illusion worked so well on me. I doubt if this
ability evolved to scare off humans.
I got the bird to make these sounds several times. It was very similar most
times, but a couple of times it wasn't quite as convincing or spirited. The
first time I heard it, I spun around to face the big bird coming at me, but
there was only a little black bird (perhaps seven inches long) sitting in a tree
about thirty feet away.
I've never come across any information on an animal using psychoacoustics to
create an illusion.
I'd appreciate any contacts or ideas on this. I'm not a bird watcher, but I am
interested in psychoacoustics because of recordings that
I make. This is why I knew what I was hearing. I have heard psychoacoustic
illusions of various kinds, but all of these were produced with software, not
animals.
Regards, Bob
Robert A. Yourell
Preparing people for challenges
"Sounds for Inner Space(tm)"
Mental Health Resources
Yourell.com
619/377-1570
Toll free: 877/266-8880
San Diego, California, USA
|