The National Library of Wales in Aberystwyth has become part of a new sound archive network.
It will become one of 10 "sound preservation centres" that will work with the British Library to protect rare and unique recordings as part of a £18.8m project.
In Wales alone, 5,000 items will be digitised.
Lona Mason, visual images librarian at the library, said it was "a race against time" to save the recordings.
"They're all on various formats, from old wax cylinder recordings, vinyl, tape recordings and cassettes, and they're vulnerable because they're decaying," she told the Newyddion 9 programme.
"Also, we don't have the machines to play these type of formats anymore."
The Welsh material will include interviews with Welsh migrants to North America and Patagonia, dialect recordings, interviews with industry workers, their families and the community, archives of Welsh traditional music and political speeches by national politicians.
Linda Tomos, The National Library of Wales' chief executive, said: "This is great news for sound collections in Wales. The National Library is delighted to be part of this important project and is grateful to the Heritage Lottery Fund for their support in making this project possible.
"This project will significantly contribute towards developing skills, providing training and preserving our sound heritage."
The British Library estimates that 500,000 recordings in total could be saved via the project, called Unlocking Our Sound Heritage.