How does parrot speech work?
November 25, 2006 1:55 PM   Subscribe

How do parrots mimick sounds like b, p, m, v? They don't even have lips.
posted by evariste to Science & Nature (12 answers total) 6 users marked this as a favorite
 
How does a speaker reproduce these sounds without lips? I imagine parrots modulate their voice to appropriate frequencies, in a similar manner to your average magnetic speaker.
posted by clord at 3:01 PM on November 25, 2006


They don't even have lips.

They don't have a human larynx, pharynx, vocal cords, tongue or human teeth, either. Their mimicry is based on an entirely different physiological airway, skeletal and muscular structure.
posted by frogan at 3:06 PM on November 25, 2006


Best answer: Very interesting question. Never even occured to me before to wonder, but now that you've asked, I must know the answer.

There doesn't seem to be a huge quantity of research on the topic, but I found one particularly relevant paper: Acoustic and articulatory correlates of stop consonants in a parrot and a human subject. The research involved an African Grey parrot named Alex, who could produce over 100 English 'utterances,' and focused primarily on word initial-stops, voiced /b,d.g/ and voiceless /p,t,k/.

The researchers, Patterson and Pepperberg, used vhs recordings, x-rays, and infrared videos to record how Alex made his sounds. They recognize that, although a parrot can mimic human speech with startling similarity (the phonetic similarities and dissimilarities are also discussed in detail in the paper), the mechanisms of production must necessarily be different:

"Alex's /p,b/ production is intriguing because he lacks lips. Ventriloquists produce /p,b/ with tongue taps and laryngeal and pharyngeal constriction instead of lips; Alex's anatomy also likely requires alternative strategies."

They think that Alex probably uses his esophagus, trachea, and glottis to create pressure build-ups and bursts that mimic the bursts created by our lips when we say a /b/ or /p/. The sound is also probably modulated by the placement of his tongue and the degree of beak openness.

P&P didn't look into other sounds produced with the lips in humans, but I imagine that answers would be similiar. Parrots create similiar effects with different sets of tools. According to Gabriel Beckers et al, "Human speech originates from independent modulatory actions of a sound source, e.g., the vibrating vocal fols, and an acoustic filter, formed by the resonances of the vocal tract (formants). Modulation in bird vocalization, in contrast, is thought to originate predominantly from the sound source, whereas the role of the resonance filter is only subsidiary in emphasizing the complec time-frequency patterns of the source." So, when birds produce the sound in the larynx, it is more complex than that produced in the human throat; as such, it doesn't need as much shaping as it comes though the mouth. Becker et al do note, however, that birds use their tongues in strikingly human-like ways to regulate sounds.
posted by bookish at 3:07 PM on November 25, 2006 [5 favorites]


A few months ago one of the blue FPP's was to a video clip of a jungle bird who was able to reproduce the sound of a camera film winder, and a chain saw, and a bunch of other non-natural sounds it had heard.

I once heard a mocking bird reproduce the sound of a school fire alarm claxon. Definitely a strange experience.
posted by Steven C. Den Beste at 5:03 PM on November 25, 2006


My African Grey parrot makes a long kissing smack that can drag out for 15 seconds. Her beak is opened with her tounge arched into her upper beak.

She will call the kids by name in my voice, then call me in their (3 different) voices. Things get a little confusing at times...
posted by JujuB at 7:38 PM on November 25, 2006


A bird's vocal organ is called a syrinx. Might help in googling answers .
posted by squink at 7:49 PM on November 25, 2006


a video clip of a jungle bird who was able to reproduce the sound of a camera film winder, and a chain saw, and a bunch of other non-natural sounds it had heard.

David Attenborough: The Lyrebird
In April 2006, to celebrate naturalist David Attenborough's 80th birthday, the public were asked to vote on their favourite of his television moments. This clip of the lyrebird was voted number one. A Lyrebird is either of two species of ground-dwelling Australian birds, most notable for their extraordinary ability to mimic natural and artificial sounds from their environment.
posted by Rhomboid at 7:50 PM on November 25, 2006


Best answer: Birds and mammals are only distantly related. Our last common ancestor was something like 300 million years ago. They're descended from dinosaurs.

They do nearly everything differently than we do: external eggs, feathers instead of fur, no milk. In mammals, the male sperm cell controls the sex of the offspring; in birds it's the female's egg which does it. (Bird sex chromosomes are known as W and Z; ZZ is male, WZ is female.) Their neural systems are organized quite a lot differently than ours are; it's more decentralized. (With proper care, a chicken can live without its head, because the most essential neural control is down in its body instead of being concentrated in its skull.) They don't have teeth.

There's no reason why their mechanisms for making sounds should be anything at all like ours; nothing else is.

And an audio speaker can make the sounds of human speech, even though it doesn't have a tongue or lips...
posted by Steven C. Den Beste at 9:52 PM on November 25, 2006


Response by poster: (With proper care, a chicken can live without its head, because the most essential neural control is down in its body instead of being concentrated in its skull.)

Steven-interesting! So if, hypothetically, I wanted to kill a chicken as humanely as possible and be sure it was very quickly dead, where would I slash it, or what would I do to it?
posted by evariste at 11:33 PM on November 25, 2006


You cut off his head. Mike the Headless chicken is the famous chicken he's referring to and it was poorly beheaded.
posted by chairface at 11:52 PM on November 25, 2006


Best answer: It also has to do with what we want to hear. I saw an episode of Scientific American Frontiers where Alan Alda watched a screen and could clearly hear a "b" sound as the onscreen person spoke "ba ba ba," but when the onscreen image's mouth was covered, the sound distinctly changed to "d" - "da da da." The point of the show was more about how much lip reading factors into speech, but I think it's also applicable here, about what we as humans want to hear.
posted by IndigoRain at 12:53 AM on November 26, 2006


Best answer: The effect referred to in IndigoRain's post is the McGurk effect. How we perceive a sound is very much related to the surrounding sounds and what we expect to hear. The exact sound a parrot makes may not truly be a /b/ or /p/ or /t/ or whatever, but it could easily be close enough and be in the right context to sound like one to us.
posted by terrynutkins at 5:01 AM on November 26, 2006


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