Here is what the Backdoor Broadcasting Company says about their free academic podcasts service:
Welcome to the website of the Backdoor Broadcasting Company. We are a mobile audio webcasting service, which concentrates on recording academic research. We are hired by universities, learned societies and research institutes to record their research as presented at conferences, symposia, workshops, public lectures and seminars and to disseminate it to a ready-made world-wide audience.
Once we have the recording, it is edited to the required specification and the sound is enhanced. Then each recording will be presented on its own individual webpage, with additional information, such as abstract and/or publications. Every page can be linked or embedded to other pages and all carry social network buttons, as well as RSS feeds.
The website here serves as the archive, which can be searched by name, date, event and keywords (tags). All recordings are free to the listener and are covered by a Creative Commons licence, which means you are free to download them and to pass them on. All legal aspects of recording and dissemination can be found here.