What statement best describes demodulation?

Demodulation refers to the process of extracting the original information or intelligence from a modulated carrier signal. In radio communications, this is essential because the information (such as voice, data, or video) is often transmitted by altering a carrier wave's characteristics. This alteration could involve changes in amplitude, frequency, or phase, depending on the modulation technique used.

When a receiver gets the modulated signal, demodulation enables the receiver to retrieve the transmitted data by reversing the modulation process. This is critical to ensuring that the intended message can be interpreted correctly at the receiving end. The correct choice emphasizes this core function of demodulation, highlighting its role in the communication process.

The other choices focus on different aspects of signal processing or interference. Detuning a receiver to remove unwanted signals, for instance, is related to tuning rather than the extraction of data. Removing atmospheric noise pertains to signal quality and clarity but does not directly refer to the fundamental process of demodulating the information. Lastly, the separation of TELEX signals from voice signals is a specific application of signal processing rather than a general definition of demodulation.