JACKI LYDEN, HOST:

Now for the nonfiction story of Peter Less, a man whose work inspires interpreters and translators everywhere.

NATALY KELLY: He was a survivor of the Holocaust, and all of his family members - his parents, his siblings, his grandmother - were killed in Auschwitz.

LYDEN: That's Nataly Kelly. She's written a new book with Jost Zetzsche called "Found in Translation: How Language Shapes Our Lives and Transforms the World." She interviewed Peter Less at his home in Chicago about a year ago.

KELLY: He went on to become an interpreter for the Nuremberg Trials, which is where the Nazi war criminals were tried, and he was the voice of the masterminds of the Holocaust.

(SOUNDBITE OF TRIAL)

UNIDENTIFIED MAN: The defendants conclude guilty or not guilty of the charges against them.

PETER LESS: Hermann Wilhelm Goring. (Foreign language spoken)

KELLY: He was the one who was enabling them to communicate so that justice could be carried out, at least in the legal sense.

LYDEN: And as Kelly writes in her book, Peter Less interpreted for the very people who murdered his entire family.

KELLY: To think about how hard it must have been for him to know that he was serving as the voice of the people who were responsible for the deaths of his family members really hit me. It really made me realize how difficult that must have been, because as an interpreter, you're constantly trying to remain neutral and detached and, you know, be impartial and convey that information in a way that is authentic and is loyal to the source.

LYDEN: Natally Kelly knows something about interpreting. She's been in the business of translation for nearly 20 years. And in cowriting "Found in Translation," she asked Peter Less how he was able to do what he did.

KELLY: He basically just said: You have to detach, and you have to just act like a machine. You have to shut off your emotions, and you have to just do that job faithfully. And it's when you rise to the occasion, you know, that is the true sign of greatness, that he was able to do that under such circumstances. Not everybody could. You know, there were many interpreters through the Nuremburg Trials who had to be dismissed because the testimony and the things they were interpreting were too difficult for them, too emotionally disturbing.

LYDEN: Natally Kelly, writing about the history-making interpreter Peter Less in her new book "Found in Translation: How Language Shapes Our Lives and Transforms the World." Transcript provided by NPR, Copyright NPR.