Video: Researchers have created an artificial tongue to help them find out more about how a mouth produces sounds.
THE pink, fleshy tongue curls up and down inside the bare skull鈥檚 jaws as it talks, as if mouthing a silent prayer. This is no excerpt from a bad horror film, but an animatronic tongue designed to improve the accuracy of speech-recognition software.
鈥淭he tongue is designed to improve speech-recognition software鈥�
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Existing systems are only reliable if people talk in a steady, uniform manner. In reality, speech varies depending on where you are and what you鈥檙e doing. For example, you may start slurring your words when you become tired.
Feeding recognition systems with larger and larger databases of recorded speech has not significantly improved their ability to cope with such variation, says Robin Hofe of the University of Sheffield, UK. He believes we need a better understanding of how the mouth produces sounds if we are to develop better software.
However, getting data from inside a human mouth is difficult. 鈥淵ou would need to embed electrodes within the muscles of the tongue,鈥� he says. This would be a painful procedure, and would also be unlikely to produce accurate results.
Hofe and his supervisor, Roger Moore, think they may have found a solution with Anton, a mechanical tongue and jaw that accurately mimics the muscular activity used to produce sounds. The tongue is made from a soft silicone called EcoFlex, which changes shape under pressure without losing its volume, like a real tongue. Embedded within the silicone are seven layers of fibre mesh, each attached to a motor. The meshes help to spread the movement produced by the motors across the tongue, mimicking muscular control. Additional motors control the jaw 鈥� a plastic cast from a real skull.
So far, the researchers have compared Anton鈥檚 movements with MRI scans of real mouths making vowel sounds. The prototype successfully mimicked the movements required for the vowel sounds 鈥渁鈥� and 鈥渦鈥�, but struggled with 鈥渋鈥� sounds. They plan to embed artificial muscles, such as shape-memory polymers, inside the tongue to make it more realistic, and a future version may also produce sound. The team will present Anton at the International Society of Artificial Life conference in Winchester, UK, starting on 5 August.
