It was both my parents who knew, and they tried some mild intervention. Nothing extreme like being sent away for anti-gay conversion therapy, I'm not sure that quackery existed back then.
One method was hypnosis by an MD in his office. I don't believe it accomplished anything. BTW, I was not told the true reason for the sessions, instead that they were to address my "nervousness".
Another worked a little better: getting a home tape recorder. I wasn't told the real reason for that, either, other than being a parlor novelty to record and play back voices for our amusement, and to play some musical recordings. On an open reel-to-reel in 1962.
At the first playback I realized what an embarrassing, over-accentuated, faggy voice I had. Horrified, I ran into my bedroom and wouldn't come out for a day. And for the next week I hardly spoke unless necessary, in clipped, short sentences.
I began to work on making my voice sound more manly, and deeper. As flat and emotionless as I could, almost robot-like.
A few months later the recorder disappeared without explanation (no music was ever bought for it), and it was never discussed again by my parents. But that gimmick did seem to work, because I lost most of my effeminate sound on my own, without my parents ever needing to correct me about it themselves. Nothing like feedback and harsh reality.
Another earlier approach was boys summer camp. But common in the 1950s for many boys, to "toughen us up" and make sure we grew up to be sturdy "red-blooded" American men. Frighteningly like concepts of the German "Master Race" and the Hitler Youth.
But the very primitive camp my parents chose may have backfired on them, and produced an opposite result. By my second summer camp at age 9 I found myself oddly attracted to our young, college-age camp counselors. Every 15-boy cabin had 1 counselor assigned 24/7, and he'd sleep in our cabin, dress with us, hike and skinny dip in the forest with us.
I'd never seen naked adult males before, and it gave me a thrill. And each summer I'd form a crush on my counselor. Guys who also had to mentor us, and be our surrogate big brothers. And who never did anything inappropriate with us, I might add. So I guess by 9 I was feeling my orientation, but still didn't understand what it was.