Well, maybe so. He turned to Lillian.
"What did you find out?"
"Well, there is a common characteristic in all four sounds. A little patch on the screen at seventeen-twenty cycles. The odd thing is that when I try to repeat the sound, it isn't there."
Odd indeed. If a Svant said something, he made sound waves; if she imitated the sound, she ought to imitate the wave pattern. He said so, and she agreed.
"But come back here and look at this," she invited.
She had been using a visibilizing analyzer; in it, a sound was broken by a set of filters into frequency-groups, translated into light from dull red to violet paling into pure white. It photographed the light-pattern on high-speed film, automatically developed it, and then made a print-copy and projected the film in slow motion on a screen. When she pressed a button, a recorded voice said, "Fwoonk." An instant later, a pattern of vertical lines in various colors and lengths was projected on the screen.
"Those green lines," she said. "That's it. Now, watch this."
She pressed another button, got the photoprint out of a slot, and propped it beside the screen. Then she picked up a hand-phone and said, "Fwoonk," into it. It sounded like the first one, but the pattern that danced onto the screen was quite different. Where the green had been, there was a patch of pale-blue lines. She ran the other three Svants' voices, each saying, presumably, "Me." Some were mainly up in blue, others had a good deal of yellow and orange, but they all had the little patch of green lines.
"Well, that seems to be the information," he said. "The rest is just noise."
"Maybe one of them is saying, 'John Doe, me, son of Joe Blow,' and another is saying, 'Tough guy, me; lick anybody in town.'"