On a late-summer morning, Terry Gross sat before a computer in her office — a boxy, glass-fronted room at WHYY in Philadelphia — composing interview questions. Gross, who wore a leopard-print scarf knotted at her neck, was typing rapidly, occasionally pausing to refer to a memoir open beside her. She swiveled in her chair to face me. ‘‘It’s interesting that she never had an orgasm,’’ Gross began. ‘‘I mean, not never, but not until later. I’d like to ask her about that, but it’s tricky.’’

Gross often talks about sex on her NPR show, ‘‘Fresh Air.’’ She frames it politically and socially, but she also comes at the subject with disarming specificity, uncovering details that seem not raw but quotidian. When she asked Lena Dunham about what it was like for her sexual partners to see her children’s-book tattoos, she elicited an answer that was almost poetic — Dunham described the tattoos as ‘‘wearing a sleeve when you are naked.’’ The exchange was also, in its way, just as boundary-pushing as the sex on ‘‘Girls,’’ Dunham’s HBO show. It’s daring to talk about sex on public radio in the middle of the day, and ‘‘tricky’’ because Gross is mindful of the needs of more conservative stations. ‘‘Sometimes in social media people act like I must be this prude,” Gross said, ‘‘and they think it’s hilarious that I’ve used a certain word.’’ But Gross talks about sexuality on the air ‘‘not because I want to be prurient’’ but because there is value in speaking honestly about something that is both essential and hidden. She uses the very public space of the interview to access tenderly personal places.

This fall, Gross marks her 40th anniversary hosting ‘‘Fresh Air.’’ At 64, she is ‘‘the most effective and beautiful interviewer of people on the planet,’’ as Marc Maron said recently, while introducing an episode of his podcast, ‘‘WTF,’’ that featured a conversation with Gross. She’s deft on news and subtle on history, sixth-sensey in probing personal biography and expert at examining the intricacies of artistic process. She is acutely attuned to the twin pulls of disclosure and privacy. ‘‘You started writing memoirs before our culture got as confessional as it’s become, before the word ‘oversharing’ was coined,’’ Gross said to the writer Mary Karr last month. ‘‘So has that affected your standards of what is meant to be written about and what is meant to maintain silence about?’’ (‘‘That’s such a smart question,’’ Karr responded. ‘‘Damn it, now I’m going to have to think.’’) Gross says very little about her own life on the air. ‘‘I try not to make it about me,’’ Gross told me. ‘‘I try to use my experiences to help me understand my guests’ experiences, but not to take anything away from them.’’ Early in her career, she realized that remaining somewhat unknown allows ‘‘radio listeners to do what they like to do, which is to create you.’’ She added, ‘‘Whatever you need me to be, I’ll be that.’’

Over the years, Gross has done some 13,000 interviews, and the sheer range of people she has spoken to, coupled with her intelligence and empathy, has given her the status of national interviewer. Think of it as a symbolic role, like the poet laureate — someone whose job it is to ask the questions, with a degree of art and honor. Barbara Walters was once our national interviewer, in a flashier style defined by a desire for spectacle. Gross is an interviewer defined by a longing for intimacy. In a culture in which we are all talking about ourselves more than ever, Gross is not only listening intently; she’s asking just the right questions.