Speech and Beaks

• Looking at the shape of a cockatiel's beak, it's natural to wonder just how it is that a mouth that shape can so closely imitate the sounds of human speech. When we talk, we form words using subtle motions of lips and teeth, motions that the rigid beak of a bird can't imitate. Yet somehow, cockatiels and other talking birds are able to reproduce the language of humans.
  
  The answer to this mystery lies in the vocal anatomy that all birds share, and in the unique nature of their voice boxes.
  
  

Vocal Sounds In Birds

• When they start, bird vocal sounds are similar in nature to the vocalizations of humans and other mammals. Like us, birds have two lungs and create sound by breathing in and out and through the air over a voice box, creating vibrational sound. However, while our voice box, known as the larynx, is at the top of the trachea, a bird's voice box, or syrinx, is positioned at the base of the trachea. Both the positioning and functioning of this organ make it distinct from ours.
  
  

The Syrinx

• A bird's syrinx differs from the larynx in that it contains no vocal cords. Instead, sound is produced in this organ through the vibration in its walls. Because of this, the sound produced by a syrinx is similar in nature to that of a kettle drum, whereas sound production in the larynx is more akin to a violin. The sound a bird makes with its syrinx is changed as muscles that alter the tension within the organ, adjusting its pitch. At the same time, the bird's diaphragm moves air from the lungs over the syrinx at greater or lesser speed to control the volume.
  Cockatiels use the motion of the syrinx to imitate the sound of words, controlling the sound while it's still in their throats.
  
  If you listen closely to the speech sounds of any talking birds, you will notice that hard, fricative consonants (such as "b" and "f") are not made, but replaced with alternatives (such as "d" and "th") in much the same way that a ventriloquist speaks without lip movement. Cockatiels in particular are better at imitating wordless vocalizations than they are at reproducing actual speech. Intonation, rather than enunciation, makes these sounds recognizable as a copy of human speaking.
  
  

Why Cockatiels Talk

• Cockatiels are highly social creatures. In the wild, they use sound to communicate with one another in a manner similar to nonspeaking birds. However, when surrounded by humans, they will begin to imitate human sounds in order to connect socially with their new "flock." It is this drive to socialize, combined with higher intelligence, that sets speaking birds apart from others and drives them to develop this remarkable ability.