So like, when I speak into my phone while on a call, whats the process before it gets sent out to the other person? Like my voice has to be turned into a digital signal somehow? And how does what software understand any of that?
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An analog signal can be turned into digital information. We should all be pretty familiar with that at this point. This happens in CDs and DVDs, for example. So I assume that’s not exactly what you’re asking.
Interestingly, many cell phone standards specify that your voice be highly compressed before being sent over the radio link by means of a *vocoder*. This is a special processor that models the human vocal tract and extracts a series of symbols from speech being spoken by the user. These symbols are then sent over the radio link as digital information and the process is reversed at the other end. The advantage of this arrangement is that a human voice can be reduced to one or two hundred bits per second, an extremely low data rate compared to just digitizing the analog signal. This is the reason that music and other non-speech sounds so horrible over a cell phone.
Fun fact: Different human languages require different vocoders since the speech sounds different! Also, there is an annual competition for people who design these things to see who is doing the best job of compressing and rebuilding voice. It’s a whole technical field in its own right.
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