Beloved,never underestimate the power of your voice.
It is not a question of volume,it is an issue of anointing.As a believer your voice is anointed,the words that you speak convey enormous spiritual influence.I have seen whole regions change simply because an obedient person spoke forth a decree.
I have seen huge gatherings which have made very little impact,and I have seen a small handful of believers standing in agreement and obedient to the call of God that have sparked revival.
You never know the impact that your words will have when amplified and multiplied by God.
In fact,the only time that they will have no impact is if you decide not to speak out at all.