What is that noise?

What is that noise? ===================

My daughter is just over two-and-a-half years old, and has started asking what's that sound? Usually, it's a straight forward answer, like "cold air being pushed through the ducting" when the air conditioner kicks on. Today my Model X, Pensive, started making an almost theramin-like sound and I had no answer when she asked on the way home from day care.

Stepping on the accelerator resulted in an increase in frequency, letting-up a decreasing frequency. It sounded as if the motor were making the sound, but it was definitely coming through the speakers in the car, and it continued until the back-up sensors began beeping while I backed into the garage.

No updates? ----------- Oddly, the last update my car received was around June 11th, which had been following a regular release every two weeks (or fortnightly). While I thought Mr. Musk's timeline for full-self-driving in August was unrealistic, maybe the lack of releases means that they're actually planning to keep the August target, and are holding releases trying to refine FSD?