IEEE Spectrum July, 2008 - 18

books
An Exquisite Ear
the memoir of BBN
cofounder and acoustics
pioneer Leo Beranek

his memoir, by a pioneer of
psychoacoustics, is a salient
reminder of how business
and social collaboration can drive
technological innovation. For sure,
people skills aren't enough; you also
need an understanding of the underlying science to judge which contracts
to accept, never mind with whom it
is best to collaborate. It is the rare
individual who has all the qualities
needed to succeed at all these things.
Indeed, Leo Beranek's character, as
much as his talent, is the (usually
understated) leitmotif of this book.
After his Depression-era
upbringing in a financially pressed
Iowa family, a chance encounter with
a well-connected Harvard alumnus
set the stage for Beranek's move to
Cambridge, Mass., for graduate school.
There, during World War II, Beranek
and his Harvard colleagues worked
under contract for the U.S. military
on a project to reduce cockpit noise
so that pilots could communicate
during flight and battle. This research
constituted foundational work not
only in noise reduction but also in the
intelligibility of speech, and it required
marshaling the talents of engineers,
technicians, and psychologists.
Later, at the Cambridge consulting
firm Bolt, Beranek and Newman
(now BBN Technologies), Beranek
and his colleagues shifted their focus
from noise control to architectural
acoustics, a decision which now
seems natural and obvious, but which
required imagination and courage at
the time. There were triumphs, such
as improvements to the Tanglewood
Music Shed, and there were also
qualified failures, such as the saga
of Philharmonic Hall (now Avery
Fisher Hall) at Lincoln Center, which
24

NA * IEEE SpEctrum * July 2008

on the directionality of
the author goes to some
length to analyze. This
echoes and their effect
on the cross-correlation
section of the book is
primarily about business
of signals at the two
and social relationships,
ears. Still, it is clear that
Beranek's knowledge and
including encounters with
famed musicians such as
love of music informed
the conductor Herbert
his engineering efforts,
von Karajan and the
and this synthesis
violinist Jascha Heifetz.
certainly contributed to
concert hall successes.
The discussion of
architectural acoustics,
This is a memoir, not a
riDing tHe
however, is disappointing,
treatise, and you will not
WaVeS: a liFe in
find in it a deep explanation
at least to this reader;
SoUnD, Science,
I found it too abstract
of acoustics and its applianD inDUStrY
By Leo Beranek;
cation as an engineering
and marred by gaps. It
MIT Press, 2008;
proceeds as if the Sabine
discipline. But if you are
256 pp.; US $25.95;
looking
for a fascinating
reverberation formula
ISBN: 978-0-262-02629-1
(developed by Wallace
glimpse into a time unique
in American industrial
C. Sabine in the 1890s),
in combination with Beranek's
history and into a life well-lived in
pathfinding work on the acoustical
pursuit of the rewards offered by that
absorption characteristics of building
era, you could do worse. It is the spirit
of Leo Beranek that shines throughout
materials, were all that is known
this book-a spirit of confidence,
about concert hall acoustics. It gives
open-mindedness, and intellectual
scant attention to the research of
Yoichi Ando and Manfred Schroeder
adventure. -Roger Zimmerman

Playing With Cyc
one of the world's oldest
Ai projects needs your help
For more than 20 years, researchers at
cycorp, in Austin, texas, have been developing an artificial-intelligence system to apply a
modicum of common sense about the world
around us. last year the company made part
of the system available in an open-source
format, so I downloaded the half-gigabyteplus compendium of facts, inference methods, documentation, and customized Web
server and started poking around.
And you know what? Half a gigabyte isn't
nearly enough to emulate the brain.
cyc contains masses of information on
subjects as varied as cats and Anna Karenina,
linked thematically in hierarchical ontologies,
formal specifications of how the concepts

in a given area relate to one another. For
instance, it might specify that a cat's feet
are at the bottom, its head and tail at opposite ends, and so on. cyc also packs a host
of tools for reasoning about the subjects,
some formal, others heuristic. Opencyc is a
stripped-down version.
Opencyc's knowledge is good on some
things but not on others. For instance, it
"knows" about the different kinds of tactics
terrorists use, that blowing things up and
taking hostages are different kinds of
events but that both are actions that
terrorists perform. On the other
hand, although it knows that
William Shakespeare was a
poet, a dramatist, a human
being, and the title character of the comic film
Shakespeare in Love, it
can't give you a list
of his plays.

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Table of Contents for the Digital Edition of IEEE Spectrum July, 2008