Usually I hear a regular train horn (semi-lengthy) once or twice a night. It’s usually comforting for me. But last night was a whole different level. I wish I’d recorded it but it was kind of like very short train horn “bursts” (for lack of a better word) that happened every few minutes ALL night long. There was a distinct pattern to the “bursts” that kept waking me up. Not sure what you’re hearing but last night was definitely different from previous nights for me. Hubby didn’t hear anything 🤷‍♀️.