I grew up with Deaf parents and I am hearing. AMA.
I also posted this in r/AMA so I hope it's ok to post it here too.
I am what's known as a CODA (Child of Deaf Adults). Both my parents are profoundly Deaf (you can scream in their ears, they won't hear anything) and BSL was my first language.
I thought people might enjoy this too, it's me age 4 in an RNID book called Sign and Say, demonstrating BSL signs. : https://www.flickr.com/photos/missfrantical/albums/72157632971529239
The only proof I can think of is a video of me signing, so here it is: https://photos.app.goo.gl/4vX6cUBoy2RHFYcj1
Here are a few answers to the most common questions:
I signed before I could speak (started at 7 months). I did not have any speech delay as my parents made sure I was exposed to English a lot. My grandparents are all hearing and I saw a lot of them, and I went to nursery at 18 months. Some CODAs do have speech delays but it's not that common.
No, I am not an interpreter and I do not want to be one. It takes many years to qualify as a SL interpreter and while I am fluent in BSL, I am a lazy signer with bad habits and would not make a good professional interpreter. And it's hard work and the hours are rubbish.
I never really did sneak out without my parents knowing, despite being able to. When you're a CODA, your parents have to have quite a lot of trust in you and you tend to be fairly responsible IME. I understood that it was unfair to take advantage in a way that would be frightening for them because they'd be unable to contact me (I was a teenager in the 90s, before mobile phones and texting). I did however play my music loud and have very loud sleepovers. And I would just turn my back if I didn't want to talk to them, or hide my mouth behind my hand if I wanted to talk to someone else without them seeing.
I was making phone calls and interpreting for my parents by age 4. It did feel like an imposition sometimes, but the balance is that I grew up being able to take care of shit. I am good at sorting things out, making sure people understand situations, and generally adulting. I am also not shy at ALL. When you grow up with people staring at you for signing, you just learn to deal with it.
For me, the deafness is not hereditary. My mum had meningitis when she was 2, and my dad they just don't know. There's no other deafness in the family.
My house was not quiet. It was in fact very loud. Deaf people don't know how much noise they're making, so there was forever a clattering of pans, doors banging, loud farting, stomping, shouting when they had friends over, and well, the less said about mealtimes the better.
Sign languages are not universal. I cannot understand ASL.
I know there are quite a few other CODAs on here so if they'd like to join in answering questions, or have different experiences than mine, that would be welcome.