This is called "crosstalk". It used to happen in POTS reasonably often, and I have experienced it in mobile to mobile calls a few times as well.
Classical crosstalk on POTs is fairly easy to get your head around - signals from one circuit leaking out onto another circuit through EMI, e.g. wires near each other, faulty amplifiers etc.
I never came up with a good explanation for crosstalk in mobile (GSM, CDMA, ..)[1] etc as audible crosstalk doesn't seem to be possible at the radio level. In fact I would be surprised if the actual voice baseband signal is analog at any point on the network.
Nevertheless, it happens.
Most likely, you experienced crosstalk at the cellular end of your Skype call. In theory, barring some pretty severe software errors, VOIP or Skype crosstalk should be impossible.
[1] AMPS networks, sure, but the newer digital systems, no.
Comments
This is called "crosstalk". It used to happen in POTS reasonably often, and I have experienced it in mobile to mobile calls a few times as well.
Classical crosstalk on POTs is fairly easy to get your head around - signals from one circuit leaking out onto another circuit through EMI, e.g. wires near each other, faulty amplifiers etc.
I never came up with a good explanation for crosstalk in mobile (GSM, CDMA, ..)[1] etc as audible crosstalk doesn't seem to be possible at the radio level. In fact I would be surprised if the actual voice baseband signal is analog at any point on the network.
Nevertheless, it happens.
Most likely, you experienced crosstalk at the cellular end of your Skype call. In theory, barring some pretty severe software errors, VOIP or Skype crosstalk should be impossible.
[1] AMPS networks, sure, but the newer digital systems, no.