I get that "winding a clock" ratchet noise that sounds like it comes from under the dash. Usually when the car in not much warmed up, and as I ease up to a regen coast. It only last for a second or two.
The whine or whistle would be the inverter transistors oscillating as they pulse to transfer power from MG2. You'll hear the same thing in EV or when first getting off the line.
The groan is the accumulator pump increasing pressure to the hydraulic brake system.
I believe you have double posted your inquiry over in the Q&A section. That generally isn't a good thing to do inside a forum because it causes people to double post, and the conversation about your question is split up between two different threads.