"affectionate voice" is a correct and usable phrase in written English.
You can use it in any sentence where you need to express that someone is speaking in a voice that conveys affection or love. For example: "She spoke to him in an affectionate voice, filled with kindness and understanding."
Published in 1939, Thirkell's irresistible comedy of manners is the most well-known of her Barsetshire series – set in the same fictional cathedral town as Anthony Trollope's Barsetshire Chronicles, and adopting a similarly affectionate satirical voice.
When she came into the room, her old face smiling warmly, her large-boned frame moving slowly and deliberately, her greeting so cheerful, open and affectionate, and her voice so beautiful and soft, almost whispering, it was easy to put aside his worries about his play and the time he was wasting by not being in the theatre.
"Korda's tone of voice is affectionate and urbane, his manner that of the accomplished raconteur who never spoils the story with a heavy-handed moral," Lewis Lapham wrote here last year.
Most affecting of all was Moore himself, shot often from the back, shuffling, feet splayed, to knock on doors, or from the side, trying not to laugh when somebody said something amazing, and talking through the film with his Michigan accent and his voice too affectionate to be sarcastic, too forceful to be merely funny.
Empedocles, Sophocles, Aeschylus, and Thucydides receive the tribute of the most advanced and abstract modern science every night, in the calm voice of this affectionate brother who keeps his sister company.
When they were not living together they corresponded frequently, and Austen often tried out different voices—"gossipy, jokey, affectionate"—to make her laugh.During this time the movements of family followed the flows of inheritance; a vexatious matter that drives Austen's narratives.
He sang "We're Going to Be Friends" from the group's current album, "White Blood Cells" (Third Man/V2), in a voice so gentle and affectionate that one suspected he was hiding a monstrous secret.
Ms. Glorsky took the stage on video in Nuria Olive-Belles's "Voice Amidst the Wings," an affectionate, revealing look at the woman, her profession and the dance history she has witnessed firsthand in her 40 years on the job.
Later the musicians joined voices again for a warmly affectionate rendition of "The Weight," the late-'60s Band song that already feels twice its age.
