You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Doctor_Who

Context:
Some episodes have been returned to the BBC from the archives of other countries who bought prints for broadcast, or by private individuals who acquired them by various means. Early colour videotape recordings made off-air by fans have also been retrieved, as well as excerpts filmed from the television screen onto 8 mm cine film and clips that were shown on other programmes. Audio versions of all of the lost episodes exist from home viewers who made tape recordings of the show. Short clips from every story with the exception of Marco Polo, "Mission to the Unknown" and The Massacre of St Bartholomew's Eve also exist.

Question:
How did the BBC get audio versions of the lost episodes?

home viewers who made tape recordings of the show