Every time water is used the sound of pressure coming from the outside runs for a long time

The water pressure may have been adjusted or re-routed. The water from the toilet may be from the attic water tank (Gravity fed) There may be an airlock possibly..it's hard to say without being there.

It could be that the cold mains stopcock was not fully open to begin with, the Plumber may have turned it off to do his work (sounds like a ballcock in one of the tanks in the loft), then when he turned it back on he opened it more than it was in the first place. You then may be hearing a gushing noise due to the increase in pressure in anything connected to cold mains pipes. To remedy this, it may be worth closing the stopcock down a bit (clockwise) a quarter turn or half turn when you are getting this noise or until your (partially) closing the valve stops the noise. A lot of people need to keep their stopcocks half closed or barely open due to high mains pressure. Obviously don't close it fully or to the point it affects taps/showers/appliances! If you turn it down a little and it stops the noise it can be left like this as long as there is adequate flow at all water outlets, hot and cold. As the other Heating Engineer answered - it's difficult to say on this one without actually being on site to see/hear what's happening. Hope this was of some help.