Hello Gonz. You can go back to whatever mobile phone you want, you will always get the same noise when you use the device (especially in making calls). The sounds you're hearing are probably harmonics from EM-fields in your device. If you don't want to carry these fields in your pocket don't use a cellphone.

Older phones with no data make just as much noise - just place them near a radio or speaker while making a call. That sound is also a harmonic of the data communication with the phone and cell-tower who work on 800MHz-1.9GHz range depending on the band your operator uses.

Calls on cellphones are just live-streams of sound data sent over a primitive network system intentionally designed that way - to take your money. As soon as VOIP got out there all cellphone companies should have been driven out of business. But people are creatures of habit. We're so used to paying bills its difficult to accept that we deserve anything for free.