A power conditioner. I won't get into brand specifics, you can research that. What's happening is that devices like compressors which are found in refrigerators, AC compressors, etc. draw a large amount of current at startup, much larger than when they're on at "steady state". These current spikes cause noise on the power lines throughout the house and voltage drops because of the large current draw. This is what you're seeing. Given that the AC compressor is probably 240V 3-phase, changing to another outlet won't help as the effect is being felt in the entire power grid of the house. A power conditioner and/or regenerator such as PS Audio Power Plant, into which you would plug you TV and audio equipment should take care of these effects.
