Is it possible a microphone sounds different when user hold it(or not)?
I've flagged this question to be moved to a more appropriate SE site, but (to expand on what Eugene Sh. said) the answer can be deduced from the advice given to pro mic users:


  Vibrations will not only reach the microphone through the mic stand. They can also enter the microphone body through the XLR connector and the cable, particularly if it is quite stiff. The best way to overcome this is to use the lightest and most flexible cable you can, and to clamp or tape it firmly to the stand to stop vibrations being carried into the mic. Location sound recordists for film and television use very light flexible tails between the mic and pole, and then a more robust cable back to the mixer, simply to avoid vibrations coming from this means of entry. Vocalists using a hand-held directional microphone can isolate cable vibration by making a loop of cable and trapping it between the fingers (not touching the microphone body) so that vibration along the cable is stopped when it reaches the hand, the onward loop to the mic being (hopefully) vibration-free. This technique also avoids straining the XLR connector with the weight of cable as the vocalist moves about the stage.




There are couple more things you need to know about MEMS:


Their natural frequency response is usually quite far from flat. So there's [mandatory] electronic post-processing. See this comparison of a MEMS mic and a [conventional/large] electret frequency response from a NASA study





MEMS often get advertised as omidirectional, but that's only true of the sensor itself. Once it goes into whatever body (especially something as bulky as a phone), they stop being all that omnidirectional: