However, 900-MHz signals can be picked up by most commercially available radio scanners. A 2.4-GHz cordless phone will be more expensive than lower frequency phones. Higher frequencies will provide greater range to your phone and offer more channels for your phone to use. Analog signals tend to be more noisy, or prone to interference with respect to sound quality. In addition, analog signals are easily picked up and interpreted by radio scanner.
Digital technology allows the phone signals to sound clearer and are more secure.
DSS digital technology spreads the digital information in pieces over several frequencies between the receiver and the base, thereby making it almost impossible to eavesdrop on the cordless phone conversations. A cordless phone with DSS is the most secure. So, if the base is capable of searching more increments, it can more easily find a frequency pair that is clear from interference. Generally, the higher frequencies will have more power to transmit and receive, and so will have a greater range. Digital phones will have clearer sounds over the same distances than analog phones.