Yes, when degaussing your monitor via the OSD, it is normal for the monitor to make a relatively loud noise. Please be aware that many models will not degauss more than once within any given time period (up to 10 minutes). This is due to the unit having a temperature sensitive resistor. While the unit is degaussing, the resistor increases in value with heat and once it reaches a certain temperature, the resistance will rise and prevent voltage from reaching the degaussing coil. This is what stops the degausser, and this device's resistance will decrease as it cools back off, enabling the degauss function to operate again. This is an intentional design and is an industry standard, not just for Philips monitors. Please be aware that not all models in the Philips range has this manual degauss function. Some models are built with an auto degauss feature which automatically degausses the monitor when it is switched on.