The Special Design which Enables Birds to Produce Sound
Talking, or even imitating sound, is not
just a simple matter of opening and closing the mouth, as some people
believe. A complex system is required for this action to take place, and
all parts of this system must be synchronized in perfect working order.
Birds with a talent for sound mimicry enjoy all of these requirements
and demonstrate their ability in extraordinary ways.
Some of these species have a talent rarely found in any other creature
except man. The best example of this are parrots, which can imitate, in
addition to human speech, a wide range of sounds that even humans can't
duplicate convincingly-for example, as the creaking of a door, the cap
being removed from a bottle, a ringing telephone, or a tune being whistled.
This talent to imitate, observable in parrots and some other bird species,
is not an ability that can be acquired by coincidence. For any living
creature to imitate a sound it has heard, it needs to have complex physiological
structures already in place. Particularly in the case of birds that can
closely imitate the human voice in terms of tone, stress and expression,
these structures must be very sophisticated.
For a bird to reproduce a word or a melody it has heard, it needs to
have an appropriate physical structure. Its sense of hearing must be functioning
perfectly, and it must be able to memorize the information received by
the senses and the ability to conceptualize meaning in its own terms.
People are astonished the first time they hear a parrot say "Hello!"
when the phone rings, ask "Who is it?" when the doorbell rings, or greet
someone familiar by name. But even though it's an astonishing achievement
for a bird to say even one word, many don't really give it due consideration.
Over time, they may even come to see it as normal and commonplace.
Not only does the bird see and recognize the person
approaching; what's more, the bird knows how to react to a person it knows.
It remembers-and reproduces-words it associates with that person. This
is evident proof that the bird has an accurate memory. If we consider
that some species of birds seem to understand questions they are asked
and give a seemingly logical answer, the issue becomes even more complex.
One important example of this is a trained grey parrot by the name of
Alex. When he's presented with a red (rose) piece of paper and asked "What
color?" he answers "rose."4 In later sections, we'll
mention more of this parrot's skills in more detail.
For a long time, it was thought that parrots
and other talking birds merely imitated, but recent research has
shown these creatures to have remarkable mental abilities.
A bird possessing such talents is a great wonder of creation, for birds
and other animals do not have free will and reason, and do not share the
human characteristics of thought, the ability to make conscious decisions
and the determination to carry them out. The ability to talk and imitate
sounds is taught by God to certain species of birds. These creatures do
not talk because of their own rational thought, will or consciousness,
but through God's inspiration. In a verse of the Qur'an, God conveys that
He is supreme over all living creatures: "… There
is no creature He does not hold by the forelock…" (Qur'an, 11:56)
All the wondrous characteristics of birds that can imitate sounds are
just part of the evidence God shows to man so we may witness the magnificence
of His creation.
The Physical Formation of Sound in Birds
You might assume that in order for a parrot to be able to imitate the
human voice-to use a person's same spoken words, stresses and pronunciation-they
must possess a larynx whose structure is similar to a human's. However,
the structure of the human larynx bears no resemblance to these creatures'
physical structures. The larynx, vocal cords, tongue, lips, palate and
teeth that humans use in speech are completely different in birds, and
some do not exist at all. But even though all birds lack these structures,
still these species can reproduce phrases spoken by humans-and in the
same tones. If we consider that a person without a tongue is unable to
speak or that we lose our voice if the vocal cords are damaged, it's also
worth considering that parrots, budgerigars, and mynahs, members of the
crow family, have completely different physical characteristics which
nevertheless enable them to talk in the same way as humans.
There are other differences between the systems that
humans and birds use to produce vocal sounds. We produce most sounds d
by expelling air from the lungs through the larynx. Different sounds are
created, according to the degree of vibration of the vocal cords. The
position of the tongue and lips and the flow of air through the mouth
or nasal cavity are only a few of the many other factors affecting sound
production. The pharynx, found in humans, lets the tongue divide the vocal
tract above the larynx into two cavities with their own distinct resonances.
Where these resonances occur, the overtones of the frequencies (or number
of vibrations) from the vocal cords are amplified. Formants (from the
Latin formare: to shape, or form) are resonant frequencies of
the vocal tract, the natural shapes that air assumes in the vocal passage.
When you make a consonant, for example, this has an effect on the formants
of the neighbouring vowels, raising or lowering formants as the vowel
sound gets closer to the corsonant. Experiments have shown that two formants
are sufficient in order to differentiate speech sounds from each other.
Birds have no larynx similar to a human's, but do have a special vocal
organ, known as the syrinx, that enables them to produce sounds. In birds,
air from the lungs passes through this organ. In a sense, the bird's syrinx
is the equivalent of our human larynx. One of the principal differences
is that in humans, our vocal cords are positioned closer to the windpipe.
So far, the fact that the bird's syrinx is deep inside the body has prevented
scientists from obtaining a complete answer as to how birds produce sound.
Scientists have filmed birds using infra-red and x-ray cameras, and have
made close studies of their song and speech by means of fiber-optic microscopes
inserted in their throats. Yet we still cannot explain the physical process
by which birds produce song and imitate sounds.
The human voice box is located in our throats
and therefore, close to the mouth. Birds, on the other hand, have
their vocal organ situated in the body. For this reason, birds'
vocal organ is affected by two airflows, as opposed to just one
as in humans. Muscles that open and close the airways on both sides
of the organ control the beginning and end points of the vocal system.
In humans, vocal sounds are produced by the flow of air from the
lungs. The lungs propel air towards the voice box, and the air passing
through the vocal cords there produces sounds that, in turn, are
transformed into speech by means of the bronchia, the tongue, the
teeth, the nasal cavity and the sinuses.
Within the bird's breast, its vocal organ is like a
branched instrument, located at where its voice box meets the two bronchial
tubes. As shown on the adjacent page, one branch of the syrinx opens into
one bronchus and the second branch into the other; and either one of these
two bronchi can produce sound. Some birds can use either both sides of
their voice organ simultaneously, or one of the two independently and,
by this means, can produce two separate tones of the same frequency, at
the same time. They can sing a high note with one side, while producing
a low note with the other. And since the bird's vocal organ is situated
at the juncture of the two bronchial tubes, it can produce sound from
two different sources. This even allows the bird to produce two different
notes simultaneously, and even to sing a duet with itself. To a great
extent, sounds produced here are subsequently combined, giving birds the
potential of creating rich melodies. While humans use only about 2% of
the air they inhale to produce sound, birds have the ability to use it
The two-branched syrinx, located deep in the
breast of a bird, is situated where the two bronchia divide in the
windpipe. In this complex system, the vocal organ's muscles and
inner membranes affect the production of mid-tones. By contraction
of the pectoral and stomach muscles, air is directed from the air
sacs to the bronchia and the syrinx, where the air molecules vibrate
as they pass through narrow passages. Vibrations of the tympana
membrane also affect the frequency of the sound. The pressure of
the air sacs in the clavicle in turn affects the tympana membrane.
The syrinx muscles also affect the flow of air and consequently,
the quality of sound.
The syrinx is located in a pouch within the clavicle below the bird's
throat. The membrane covering this pouch is sensitive to the air coming
from the lungs, and its elasticity and complexity of the membrane are
factors that determine the quality of sounds. The sound quality is also
affected by the length of the windpipe, the constriction of the voice
box, the neck muscles, structure of the beak, and their respective movements.
In short, the complexity of the birds' syrinx determines the complexity
of the sounds they produce. Its muscles affect the air flow and consequently,
the quality of the sound. In parrots, budgerigars, and some songbirds,
the syrinx has a greater number of muscles, and its structure is more
Furthermore, the different techniques that parrots and
budgerigars employ for imitating the human voice are most effective. Like
humans, parrots have thick tongues that enable them to produce sounds
resembling ours. Sound is produced by blowing air through two separate
places in their syrinx, and at the same time producing the independent
sounds required to produce consonants. The initial sound from the syrinx
is shaped with the help of the throat, and then in the mouth with the
tongue. In their research studies with grey parrots, Dianne Patterson
and Irene Pepperberg reached important conclusions on vowel production:
Due to the radically different anatomy of this parrot's vocal organ, even
though they lack teeth and lips, they can produce sounds that closely
resemble sounds produced by humans.7 Indeed, parrots
and budgerigars can quite clearly imitate sounds such as "m" and "b,"
which we normally produce with the help of our lips.
Budgerigars, however, due to their small size, are not able to use the
same technique as parrots. Using their syrinx to create frequencies from
2,000 to 3,000 Hz, they then add on a second vibration. This system is
known as frequency modulation or FM, the principle behind the AM (amplitude
modulation) radios to be found in practically every home. These days,
many FM broadcasting stations add low transmitters to their signals which,
in common with normal signals, are adjustable through a transmitter, but
are of a very high frequency. While the frequency of normal signals varies
from 20 to 20,000 Hz, the frequency of many low transmitters starts at
56,000 Hz. The main reason for using the FM system is to offset the major
disadvantage of the AM system-namely, the interference of many natural
or man-made radio sounds, called "parasites." Because the weak signals
of AM radio are quieter than the stronger ones, differences in signal
level are formed, which are then perceived as noise. AM receivers have
no facility for cutting out these parasitic sounds.
The physical structures used in human speech-voice
box, vocal chords, tongue, lips, palate and teeth are completely
different from the structures in birds, and some are completely
absent. Even though talking birds do not possess these structures,
they are able to produce words and expressions used by humans, and
with the same intonation.
To solve this problem, Edwin H. Armstrong invented a system for eliminating
noise caused by the power of the waves. Instead of changing the transmission
signal or the strength of the transmitter, he changed the frequency of
sound waves per second. Thanks to this system, the amplitude of noise
(strength of sound waves) could be reduced to a minimum. But scientists
are still mystified how budgerigars manage to use this same system.
Of course, no little budgerigar can possibly work out for itself from
the time it is hatched how to apply a series of principles discovered
by man only after long trials. In the same way, no parrot can know that
it must produce auxiliary sounds in order to make consonants distinct
or to develop systems in its throat to enable it to do so. Also, it's
not possible for such a system to be the end product of a series of blind
coincidences. All these complex systems we have seen are without doubt,
the work of God, the Creator.
Birds' Sense of Hearing
Birds' ability to perceive sound is approximately
ten times keener than ours. Birds can discern ten different sounds
in what humans perceive as one note. Moreover, while humans process
sounds in 1/20th of a second, birds can distinguish the same sounds
in 1/200th of a second.
For birds to display their talents in communicating
by sound, song and in the case of some birds, words, they require excellent
hearing. At critical times in their lives, their sense of hearing becomes
particularly important. Experiments have shown that in order for birds
to learn their species' song, they need an auditory feedback system. Thanks
to this system, young birds learn to compare the sounds they produce themselves
with the patterns of a song they have memorized. If they were deaf, it
wouldn't normally be possible for them to sing recognizable songs.8
Birds' ears are well equipped for hearing, but they hear in a different
way from us. For them to recognize a tune, they have to hear it in always
the same octave (a series of seven notes), whereas we can recognize a
tune even if we hear it in a different octave. Birds cannot, but can instead
recognize timbre-a fundamental note combined with harmonies. The ability
to recognize timbre and harmonic variations lets birds hear and reply
to many diverse sounds, and sometimes even reproduce them.
Birds can also hear
shorter notes than we can. Humans process sounds in bytes in about 1/20th
of a second 9, whereas birds can distinguish these sounds
in 1/200th of a second, which means that birds are superior
at separating sounds that arrive in very rapid succession.10
In other words, a bird's capacity to perceive sound is approximately ten
times greater, and in every note heard by a human, it can hear ten.11
Moreover, some birds are also able to hear lower sounds than we are. Their
hearing sensitivity is so finely tuned that they can even tell the difference
between pieces by such famous composers as Bach and Stravinsky.
Birds' extremely sensitive hearing functions perfectly. Clearly, each
of this sense's components is created by special design, for if any one
failed to work properly, the bird would not be able to hear anything.
This point also disproves the theory that hearing evolved or emerged gradually,
as a result of coincidental influences.