MELISSA BLOCK, host:
In July of 1969, when Neil Armstrong stepped off the lunar module Eagle and onto the surface of the moon, we all know what he said.
Mr. NEIL ARMSTRONG (Astronaut): It's one small step for man, one giant leap for mankind.
BLOCK: But wait, quibblers say, that's a tautology. One small step for man, one giant leap for mankind? That's like saying one small step for mankind, one giant leap for mankind. But when Neil Armstrong returned to Earth and saw the transcript of his remarks, he said no, no, what I actually said was, that's one small step for a man. Let's listen again.
Mr. ARMSTRONG: That's one small step for man -
BLOCK: Well, this is where Peter Shann Ford comes in. He's a computer programmer in London. And Mr. Ford, you think you have found that missing A?
Mr. PETER SHANN FORD (CEO, Control Bionics): I'm pretty sure about it, Melissa. Because even though you can't hear it because it happened so quickly, 35 milliseconds, 35 thousandth of a second, you can see the voice print.
BLOCK: Voice print? How do you see a voice print?
Mr. FORD: When we speak we generate sound waves and when microphones pick those waves up they can be transmitted electronically onto a computer screen. So you actually see the waves going up and down as we're speaking. And when you have a look at everything that the human voice creates, you can actually see elements that come out, air pressure waves that come out of the mouth, which not be audible, either because they're too low to hear or too far above the audible range or because they're too fast. And in this case, there were a little bit of both. They were slightly inaudible and they were only 35 milliseconds long.
BLOCK: And can you hear it, or you just see something in that pattern?
Mr. FORD: You hear something but it doesn't sound like an A sound. But when Neil Armstrong says one small step for a man, he actually makes that sound, you can see it on the voice print. After the for, you see another little burst of sound air pressure, which is consistent with a vowel sound, and if you look at the physiology of a mouth the way the A rolls down between for and man you can actually see the pressure wave that comes out because he's kept his mouth open long enough to say a man instead of just for man.
If he just said for man, as in for mankind, you would not see that additional pressure wave. And in fact, when you look at for mankind, it's not there.
BLOCK: We'll let's listen to tit one more time and see if we can hear anything you're describing here.
Mr. ARMSTRONG: That's one small step for man -
BLOCK: Now, when you listen to that are you hearing anything, maybe that we're not hearing?
Mr. FORD: We all hear the artifact where he said for a man. But as you know, anybody who works on a microphone knows that unless you clearly enunciate the sounds, especially vowels after consonants, very often you can think you're saying and think about saying it but it doesn't come out clearly, which is why voice teachers make so much money.
But because Neil Armstrong, who has said that he doesn't say the vowels very clearly and very often drops them, he knew that. But he also knew, because he actually drafted that statement - one small step for a man, one giant leap for mankind - he knew that he meant to say it. He believes that he did say it, but he thinks that he might have said it so quickly or so inaudibly, either the microphones didn't pick it up or nobody could hear it. And in fact, it was a little bit of both.
BLOCK: This seems to be something that's troubled Neil Armstrong over the years. He has said I didn't intentionally make an inane statement. Have you talked to him about this and about what you've found out in your analysis?
Mr. FORD: What was really exciting was when I first did this analysis two weeks ago, I called an old friend, Hugh Harrison, at NASA and asked him to get this to over to Neil Armstrong. And I had put in into a paper so he could read it. And he then e-mailed back and we arranged a meeting at National Air and Space Museum in Washington.
And what we really did for the hour, we sat together and talked in front of the computer. What we just talked about, sound propagation and carrier waves, and radio signals and the microphone set up inside his headset of his spacesuit. So we talked about all of the technicalities that could affect the sound. And then we talked about the actual sound wave that he propagated when he said for a man. And at the end, he said, the technology is interesting, this presentation is persuasive. And that was about it. And that was, for an engineer, that was a good empirical statement about what we had just seen.
BLOCK: Well, Peter Shann Ford, thanks for talking with us.
Mr. FORD: It was a pleasure, Melissa.
BLOCK: Peter Shann Ford is a computer programmer in London. He believes he has detected astronaut Neil Armstrong's missing A.
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