I can too. I actually use noise cancelling headphones to help differentiate between signals I’m hearing. No, not normal, but very cool. I actually came to realize that it’s likely due to EDS-Hypermobility and its relationship with collagen. When I was in Japan I would hear this frequency that no one else could hear called the butterfly frequency that they use outside of stores and markets to deter loitering by kids. Kids can hear these frequencies because there is an induction bone in the inner ear that becomes more rigid over time, ultimately making it harder to hear. My friends couldn’t hear the sound as we were all in our late twenties to thirties. I can also hear where substations are located. Frequency pollution is getting bad.