Last week Daedalus presented his mobile ‘Ultraphone’ for silent speech. The user whispers or mouths his message silently. His voiced tone is replaced by an inaudible ultrasonic tone launched into his mouth. His tongue and palate modulate this into inaudible ultrasonic speech. A heterodyne circuit downshifts it back to an audio signal, which is transmitted.

Daedalus now has a biological use for the technique. Many animals — cats, dogs, bats, rats and many insects — communicate partly or mainly in the ultrasonic band, above human hearing. Instruments can downshift their voices into the audio band, as the Ultraphone does. But the Ultraphone also performs the converse operation. It upshifts the human voice into a range much more significant to animal ears.

So DREADCO animal keepers are now speaking to their charges on an adapted Ultraphone. Its intense ultrasonic beam lets them ‘speak’ loudly and clearly in this waveband. Its wideband microphone and heterodyne circuit downshifts the animals' ultrasonic responses back into the audio for human recognition. The ultrasonic frequency of the ‘Animal Ultraphone’ can be adjusted to the band in which the conversation seems to flow most freely.

Laboratory rats are the first subjects. These bright and companionable rodents can be tamed quite well by normal means. An added vocal channel should bring them even closer to human understanding. The DREADCO staff are trying to imitate their language, and give them ultrasonic ‘names’ that they can recognize. Bats, those ultrasonic experts, may also respond to the Ultraphone; insects are probably too dim.

But the main impact of the Animal Ultraphone will be on domestic cats. These intelligent pets are famous for their aloof independence. They notoriously refuse to learn (or at any rate to obey) even the simplest commands. To them, human speech is probably a low vague mumbling. But talked to in the right ultrasonic band, even the most suspicious cat should become alert and responsive. It might even reply in tones that, downshifted to mellow audio by the Animal Ultraphone, appeal to the human ear.

Feline–human relations will be transformed. Bonded at last by mutually appreciated vocal expression, cats and cat-lovers will bestow far more warmth and company upon each other, bringing a new and welcome closeness to a long-standing association. And the true intelligence of these friends of Man may at last become apparent.