Frank - I've been engaged in this issue for several years, including
participation on the National Wind Coordinating Committee. This is the first
time I've ever heard of anyone altering blade design to change the sound
frequency, much less it having been tested, much less it having been shown
to work.

Would greatly appreciate your sharing references of all kinds - whether
peer-reviewed or not. Anything that would point me to your source of
information.

I have to say that the architect in your firm is much like the general
public in not being aware of things that are broadly reported in major
newspapers and on radio and television news. The Washington Post has been
reporting on the bird/bat issue for well over a year. People just seem to
want to be unaware. They don't avail themselves of even the most broadly
distributed information that is out there. But I guarantee you that the
"wind energy" people know. If they claim otherwise, they are being
disingenous. All they have to do is look at the American Wind Energy
Association (their OWN trade group) website to know. Not to mention that
nearly every wind farm is opposed by a local wildlife group.

Ellen Paul
Chevy Chase, MD