Radio frequency tuning issues...help requested...please. - GameFAQs

That doesn’t look like a word, so you might be misremembering the sequence. The more common Steel Mill broadcast cipher is:

"No, sir," Alfred confirmed, his tone becoming more urgent. "It’s a medical code. Specifically, it refers to a neurological toxicity event. The subject is undergoing a specific biochemical breakdown."

2 = B 7 = G 5 = E

When you climb the tower, look at the on the left side of the control panel. Each slider has a hidden marking only visible in Detective Mode:

To hear these yourself, you typically need to have completed the main story. Open your Cryptographic Sequencer