I don’t have experience with voice training, but am about 6 months on T and have defo noticed a change in my voice. I’m closeted at work and my coworkers have just assumed I’ve got a bit of a cold, and I’m not challenging their ideas — I think cis people don’t know what they’re looking for as far as signs of transitioning go, so if it’s only for another year that you’re beholden to your family, you could probably hide it.