My subconscious has evidently been thinking about the appropriate voice modulation of Watch Constabulary security drones in order to ensure that in crowds, against background noise, or even when just being insufferable, people stop and pay attention to the Angry Bot and its Angry Bot Noises.
The traditional solution to this is, as decades of SF media has taught us, flanging.
So… would you prefer being arrested by Dalek, Goa’uld System Lord, or Reaper?
Daleks may be horrifyingly dangerous even to the Doctor, but at the best of times they still sound like high-strung pepper shakers on the verge of a nervous breakdown. Not exactly a tone of voice conducive to engendering calm compliance.
Meanwhile, Goa’Uld voices miss the mark in the other direction - they sound like someone trying WAY too damn hard to be ominous and powerful with a set of vocal chords that aren’t up to the job.