Power steering leak making loud buzzing sound more loud when turning

The car will do that when it is low on power steering fluid as the pump is working harder. Either get the leak fixed or if it is a slow leak make sure you keep the correct level of power steering fluid in the pump resevoir.

Good Luck

The power steering leak is creating bubbles in your power steering pump which gets strained more when turning, which causes it to be louder when turning. If you know where your leak is, then fix that, then try to bleed your ps system by filling up with the cap off the resevoir and turning the steering wheel max left to max left with trans fluid. if the noise is still there then your ps pump needs to be replaced along with the ps vsv located on the side of the pump.