As I just mentioned in another post, it also does it when the battery hits 20%, regardless of whether the drone is 10 feet or 100 feet away. This is really obnoxious and egregious in IMHO.
Also, sometimes RTH gets activated for loss of signal ... one or two beeps would be fine. Although you SHOULD already know this is happening, so totally not necessary. (I guess for people too busy watching TV or playing with their phone it's good to have. )