You're thinking in the frequency domain, which is natural. Try to think, instead, of what a dual-sideband suppressed-carrier signal looks like in the time domai

You're thinking in the frequency domain, which is natural. Try to think, instead, of what a dual-sideband suppressed-carrier signal looks like in the time domain. It looks for all the world like a single frequency with rapid variations in amplitude (which can be accomplished by bubbling the air through a carefully-controlled reservoir of saliva). If you can mimic the time-domain signal, you can mimic the frequency-domain signal, since they're just two ways of looking at the same thing.