Any squeaks or sounds that are emitted during a transmission are due to electromagnetic interference or EMI. EMI results when an electronic, such as a cell phone, transmits waves in a radio frequency that clashes with another electronic's operation. If a computer signal is strong enough, a phone will mistake the wave as a cell phone transmission.
Noise can result, too, if the audio amplifier's wiring for a cell phone is activated by the electric current coming from a computer. Because electronic equipment is made to produce radio waves, annoying sounds, in the form of squeaks, can occur every now and then.
Radio wave generation or unwanted noise can be reduced if electromagnetic waves are contained within the metal housing of an electronic device. However, sometimes areas in the coating or holes in a case cause electromagnetic leaks and unwanted noise.
Technically, EMI is a disruption in the operation of an electronic when it is located in a radio frequency spectrum of another electronic. Internal circuits in PCS generate an electromagnetic field in the RF or radio frequency range. As a result, the emissions can impede a wireless receiver's performance. Anyone who uses a wireless receiver and his PC at the same time will usually be assaulted with some type of electromagnetic interference or noise.