The University of Edinburgh’s School of Philosophy, Psychology and Language Sciences has created the website Sound Comparisons “to provide an overview of the variety of the sounds of the English language on various levels: in time, with our transcriptions of historical ancestor forms of English, from present-day back to Late Modern English, Early Modern, Middle and Old English, as far back even as Proto-Germanic; over geographical space; by sociolinguistic context.” More details can be found at their Information page; of the historical element, they say:
Obviously, we cannot provide recordings of the various historical stages in the development of English, but linguistic analyses do make it possible to work out what the likely pronunciations were to a reasonable degree of accuracy. With each step further into the past, however, the more and more we ‘reconstruct’, the more linguists’ confidence in the real phonetic accuracy of our transcriptions necessarily reduces. All our transcriptions for historical varieties are therefore always to be taken with this caveat in mind.
An interesting site; thanks, Paul!