The "whoop, whoop" you heard was probably not THE "whoop, whoop" as that would have been followed up a "PULL UP! PULL UP!" and you would have gone around. I'm guessing that it was the "Cavalry charge" many airplanes use as the autopilot disconnect audio alert. That alert sounds everytime the autopilot is disconnected.

The altitude call outs are from the TAWS terrain warning system and are heard on every landing. They are the height above the ground based on the radar altimeter. The calls are "100... 50... 30... 20... 10". If an ILS is not in use you will also get a call at "500". There may be some minor differences between different aircraft types.