The idea of using computers to make receiving international radio signals easier has been around since the 1970s. It was only in the '90s when governments and military forces began using the technology in force, and only in the last few years that the technology has become available and affordable for the general population.
Software-defined radios, or SDRs, combine the utility of analog shortwave radio and the precision of modern computing. An analog radio receiver can be teamed with a computer via a sound card and analog-to-digital coupler to make international radio signals — which are sometimes plagued with noise, interference and static — cleaner and easier to hear.
Additional article on the benefits of SDR radios at: https://www.kamloopsthisweek.com/entertainment/radio-edit-tools-can-help-you-listen-in-on-shortwave-radio-1.23389619