Yes, I think it might be a networking issue, in retrospect, though I don't know how I can promote myself any further without risking spamming people.
This is the tricky thing about networking, and something that I had to learn over several years. It's so much less about the "hire me!" approach and so much more about getting to know people. This takes more time and effort. I've gotten more work by getting to know people when discussing food, games, sports, books and movies than I ever got by cold emailing or spamming. Take part in local and major conferences and events. Put a face to your name and be more concerned with getting to know people right now. Then when they need audio, they'll reach out to you.
Networking isn't an overnight or even over one-year kind of deal. It's a slow pressure cooker but once it gets going, it almost maintains itself (so as long as you do great work and are a pleasure to work with. )
Best of luck!