Digitizing an analog signal, and reconstituting an analog signal from a digitized version of the analog signal

A method, comprising:

• generating a modulated signal having an instantaneous amplitude and an average amplitude by angle modulating a carrier signal with an analog audio signal;
• and
• generating a digital signal having edges corresponding to times at which the instantaneous amplitude of the modulated signal approximately equals the average amplitude.

A reconstituted audio-signal digitizer, comprising:

• a signal node operable to receive a digital signal having a first level during respective first periods and having a second level during respective second periods, the first periods having respective first durations and the second periods having respective second durations;
• and
• a demodulator coupled to the signal node and operable to demodulate angularly the digital signal by generating an analog audio signal having an instantaneous amplitude corresponding to the first and second durations.

An audio system, comprising:

• a storage device operable to store information describing first and second durations of respective first and second signal levels that compose a digital signal;
• and
• a demodulator coupled to the storage device and operable to demodulate angularly the digital signal by generating an analog audio signal having an instantaneous amplitude corresponding to the first and second durations.

A method, comprising:

• receiving a digital signal having edges;
• and
• angularly demodulating the digital signal to generate an analog audio signal having an instantaneous amplitude corresponding to durations between consecutive edges of the digital signal.

A method, comprising:

• receiving a sequence of numbers that represent first and second periods during which a digital signal has respective first and second levels, the digital signal representing a carrier signal angularly modulated with an analog audio signal;
• and
• generating from the sequence of numbers a reconstituted analog audio signal having an amplitude corresponding to the numbers.