If you hear a soft "particle" sound during startup and the sound disappears after one to two minutes as described in the "Startup noise" section, this is completely normal as the filter needs some time to warm up.
However, if the noise continues, then please try the following:
1. Please use a dry tissue/paper to clean the thin tungsten wire gently.
2. If the noise still continues, please follow the full cleaning steps of your Air Purifier by following the instructions on this link "How to clean your Air Purifier"