If 3 conditions are met, it is Muttar Mi’Ikar HaDin.
1) you are answering Amen to every single Beracha and aware of which Beracha you are answering.
2) there are at least 9 other people listening to every single word of Chazoras HaShatz.
3) noone is likely to be influenced by your actions.
Even if all these are fulfilled, it is still not recommended.