Here's Malcolm reading the letters. It's obviously mostly about Hughes, but it's interesting as well for its sensitivity (in this highly sensitive writer) to the experience of reading letters written in different media — a letter printed from a word processor being in a different media, though the paper be the same, than one  typed on an Olivetti.  

The letters from Hughes immediately drew me, as if they were the electrically attractive man himself. As I looked at the pages of dense, single-paced typing, punctuated by x-ings-out and penned-in corrections, I had a nostalgic feeling. The clotted, irregular, unrepentantly messy pages brought back the letters we used to write one another in the 1950s and '60s on our manual Olivettis and Smith Coronas, so different from the marmoreally cool and smooth letters young people write one another today on their Macintoshes and IBMs. Reading the letter giving Hughes's response to the chapters Anne had sent him of her short biography, I felt my identification with its typing swell into a feeling of intense sympathy and affection for the writer. Other letters of Hughes's that have come my way have had the same effect, and I gather that I am not alone in this reaction; other people have spoken to me with awe of Hughes's letters. Someday, when they are published, critics will wrestle with the question of what gives them their peculiar power, why they are so deeply, mysteriously moving.