I’ve been searching around for a couple of days to see if anyone noticed this. In Halo S02E07 around the 38 minute mark, Talia Perez is staring at her reflection just before Master Chief walks in to talk to her. Over the loud speaker, you can hear someone say “Tango-Hotel-Xray-one-one-three-eight”. (headphones helps) That’s a classic reference to George Lucas’ early film THX-1138. Used heavily throughout the Star Wars universe and many other films.
When I heard the 1138 part I was like "I know that number!" so I rewinded it a bit and cranked up the volume and caught the Tango Hotel Xray. It's so fast that I'm sure hardly anyone noticed. I probably wouldn't even have heard it if I wasn't wearing headphones. I love it when editors, sound engineers and VFX people throw in little easter eggs like that. It's like a little nod to us nerds. lol