Electronic appliances such as TV sets, radios and cell phones can interfere with each other and thus cause disruptions. However, most of the problems reported are barely noticeable and do not impair the device's functioning. One example is interference in a radio loudspeaker when someone standing close to the radio uses a cell phone to make a call.
To prevent this, electrical and electronic devices must meet the requirements of the electromagnetic compatibility standard (EMC). These requirements are defined in the European Union's EMC Directive and on national level by EMC legislation.