For most of us, thinking about museums and archives will conjure up images of physical relics; faded books, paintings and trinkets discovered beneath the soil. But now, the British Library is fighting to preserve something more elusive: sound. With £9.5 million in fresh Lottery funding, it hopes to digitise and release 500,000 rare and at-risk recordings over the next five years. The challenge is that some audio snippets are currently held on old formats, such as wax cylinders and magnetic tape. They're slowly decaying to a point of irreparability, and the equipment required to play them is becoming harder to source. The British Library estimates that 1 million UK sound collections could be lost in the next 15 years, so in January it started a "Save our Sounds" campaign to preserve them.