In the Twilight Zone of Sound
Gary Lawrence Murphy
garym at canada.com
Thu Nov 6 16:13:03 PST 2003
Sure, audio illusions, I could name a few, oddities of phonetics like
-ough and-uff for example, but /none/ of them came anything close to
what Diana Deutsch's research is finding ...
In the Twilight Zone of Sound
By PETER MONAGHAN
A short phrase of speech in Diana Deutsch's mellifluous voice,
with its faded English accent, loops over and over from the
loudspeakers in her sparse, windowless sound studio.
"Sometimes behave so strangely," comes the phrase.
"Sometimes behave so strangely."
And, strangely, after only a few repetitions, a striking
effect emerges. With the rhythms and cadences of her voice,
the sounds become undeniably musical.
"It matches to a simple melody playing in B major," exclaims
Ms. Deutsch, still surprised years after she first noticed the
"It shows that speech and music connect," she says, and then
speculates: "It makes sense to me to think that originally
speech" -- all speech, she means -- "was pitched as tones,"
the way Chinese and Vietnamese are today.
The auditory illusion is one of many that Ms. Deutsch, a
professor of psychology here at the University of California
at San Diego, has included on two compact discs, Phantom Words
and Other Curiosities (Philomel Records), which has just
appeared, and Musical Illusions and Paradoxes (Philomel
The illusions range from the beguilingly simple to, as she
says, "true weirdness, the twilight zone." Appropriately,
then, her first disc's introduction has a tinge of Rod Serling
as she intones: "In listening to this CD, you enter the
curious and paradoxical world of illusion. The sounds as they
appear to you are not only different from those that are
really present, but they sometimes behave so strangely as to
seem quite impossible."
In her laboratory, sitting at a bank of amplifiers, speakers,
and other sound-system components, Ms. Deutsch cues up what
she calls the "octave illusion." Through headphones, high
tones sound in one ear, low tones in the other. But when the
earphones are switched, the high and low tones are heard in
the same ears as before.
In fact, Ms. Deutsch reveals, the same pattern of alternating
high and low tones is sounding in each earphone. For some
reason, the listener's ears create "the peculiar impression
that the high tone has migrated from one earphone to the
other," and the low tone, too, in the opposite direction. "It
was a shock," she says. "It was unbelievable [to stumble on
that illusion]. It wasn't known at the time. I thought, 'Am I
crazy? Has the world gone crazy?'"
As simple as the pattern is, it is hardly ever heard
correctly. Ms. Deutsch has found that, because of differences
in which hemisphere of the brain dominates, right-handers tend
to hear the high tones on the right, the low tones on the
left, while left-handers' experience varies.
Another illusion, which Ms. Deutsch calls the "tritone
paradox," is one that confuses even accomplished musicians.
Her computer creates an organlike sound equivalent to, say,
all six C's on the piano keyboard. That is followed by the
sound of all six F sharps -- half of an octave away. When some
subjects listen to that tritone, they hear an ascending
pattern. Others, listening to the same tritone, hear a
"There is no correct answer," says Ms. Deutsch, "the ambiguity
is built into the tones themselves." The effect, Ms. Deutsch
believes, stems from the way people perceive and store musical
scales in their brains. Each note in a particular scale
resembles its counterpart in other octaves -- all the C notes,
for example, sound like C notes. Whether or not they have any
musical training, Ms. Deutsch conjectures, listeners have
their own mental image, like a clock, of which notes of any
octave are the "highest," regardless of actual pitch. So, when
they hear two notes that are half an octave apart, the first
may sound higher, or lower, than the second.
What is going on? Clearly, says Ms. Deutsch, when it comes to
hearing, "we pick and choose how to bundle things together,
rather than admit chaos." It would appear that some part of
our hearing mechanism registers pitch, another where sounds
are coming from. Sound may be thought of as a bundle of
attributes that can fragment, she says, so that one may hear
tones in the "wrong" ear. The human auditory system is
apparently more loosely constructed than the visual system, so
"in the lab you can propel it into absurdities, even though
mostly, in everyday life, it works well."
Ms. Deutsch is tirelessly enthusiastic about hearing and
sound. As a teenager, she hoped to become a professional
pianist, but her parents persuaded her to pursue a
more-certain financial future. She went to the University of
Oxford and performed extremely well in psychology and
philosophy, then came to California to earn a doctorate here
at San Diego.
She arrived just when computers were beginning to be used to
manipulate sound, facilitating researchers' ability to analyze
what, and how, people hear.
The earliest illusion she wrote about, in the journal Science
in 1970, may have implications for neuropsychology. "You'll
hear two tones, with a series of tones, or words,
intervening," she says, as she cues up another track of
Phantom Words. "Try to remember whether the last tone is
higher or lower in pitch than the first." The task proves much
harder when other tones intervene than when words do.
Cognitive and neuropsychologists have encouraged Ms. Deutsch
to pursue the implications of that finding for understanding
memory and for diagnosing the early signs of Alzheimer's
Some of Ms. Deutsch's research reveals the links among
hearing, music, and language acquisition. She is, for example,
studying the incidence of perfect pitch -- the ability to
consistently recognize and repeat sounds of a particular pitch
-- in speakers of languages such as Chinese, in which words
have different meanings depending on whether the syllables
rise or fall in inflection. She and colleagues are studying
populations of students at the University of Rochester's
Eastman School of Music and a music school in Beijing to see
if the Chinese students, who acquired perfect pitch for speech
as infants, later tend to possess it for music. "It doesn't
ring true that only some people would have perfect pitch," she
says. It may, she says, be possible to help infants acquire
The acquisition of toned speech, and of music, is strongly
influenced by culture. A population of speakers agrees that
certain sounds constitute certain words. One of Ms. Deutsch's
illusions with cultural aspects always confuses and even
bothers her test subjects, including whole classes of her
students here. In the "phantom words" illusion, she plays
fragments of words over and over. Different listeners hear
different words emerge from the mesmerizing sequences of
garbled fragments. In fact, many insist that she must have
implanted the words they hear in the patterns. "People really
do believe their own perceptions," says Ms. Deutsch. "That's
how magicians manage, isn't it? But perception is not as good
as people think it is. When people are told they've heard
something else, some think it's incredibly funny. But
sometimes I get anger."
Subjects for whom English is a second, but fluent, language,
often hear words in the language they first learned. Such is
the power of early linguistic experience, Ms. Deutsch says.
She also finds interesting differences between men and women.
Many women hear words related to romance, or "words like 'no
pie,' and 'Diet Coke,'" she says. "You can tell who's
And the men? "They tend to hear things that make them ask me
if it's OK to say them in polite company."
She is testing her belief that the phantom-words illusion acts
like a kind of auditory Rorschach test, diagnostic of people's
states of mind. People suffering from depression tend to hear
words like "attack," "blood," and "I'm dying," she says. "The
data so far is sufficient to convince me without any doubt
that this is going on."
For another truly bizarre auditory illusion, or hallucination,
she has no firm hypothesis, but is gathering data. Some
people, usually elderly, constantly hear music -- not, say,
the ringing of tinnitus, but actual tunes. In fact, of the
dozens of people in several countries who have reported their
experiences of this as-yet-unnamed syndrome to her, almost all
hear male choirs singing patriotic songs, or a single male,
baritone voice. Talk about a twilight zone.
Those with the syndrome show no signs of psychiatric illnesses
or brain tumors; they simply hear singing. "It's externalized
music; it's not tunes running around in your head," says Ms.
"Some people don't mind, and even find the music pleasant,"
"But with most people, it drives them nuts."
This article is available online at this address:
From the issue dated November 7, 2003
Copyright 2003 by The Chronicle of Higher Education
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