An article called The Power of Sound by Martin Bonney and Deborah Blaxell of Epiq Systems, and published in The Lawyer (it is at page 26 here), makes it clear both that sound recordings have moved to the mainstream in eDiscovery / eDisclosure and that technology is evolving rapidly to deal with them.
The article makes the point that one can sit people down to listen to recordings and be reasonably sure that they will capture anything of importance. The fact is, as the article observes, it will almost never be proportionate to manage audio files in this way when it can take up to four hours to transcribe one hour of audio.
Most of the article is taken up with helpful descriptions of the context and of the rapidly advancing technology in what remains a new area. The passage to which I would draw your attention specifically comes right at the end when the authors stress the need for “a considered and well-thought-out plan and consideration of the available options”
The new procedural rules taking effect on 1 April in England and Wales require parties to understand, to discuss and to make proportionate proposals for the management of their electronic evidence. What that last paragraph reminds us is that managing audio is not something to be done on the fly. Even if the audio material lacks some of the complexity referred to in the article – foreign languages, for example – substantial amounts of time will have to be set aside to handle it.
As with everything else to be disclosed, it is important not merely to be able to say what exists, but to be able to give an assessment of its potential importance and of the time likely to be needed to deal with the recorded material – the elements of proportionality. That requires early attention to it so that its implications can be discussed along with the other material.