Psalm 142:1-7 (ESV)
With my voice I cry out to the Lord;
with my voice I plead for mercy to the Lord.
 I pour out my complaint before him;
I tell my trouble before him.
 When my spirit faints within me,
you know my way!
In the path where I walk
they have hidden a trap for me.
 Look to the right and see:
there is none who takes notice of me;
no refuge remains to me;
no one cares for my soul.
 I cry to you, O Lord;
I say, “You are my refuge,
my portion in the land of the living.”
 Attend to my cry,
for I am brought very low!
Deliver me from my persecutors,
for they are too strong for me!
 Bring me out of prison,
that I may give thanks to your name!
The righteous will surround me,
for you will deal bountifully with me.
Do you pray out loud? Sometimes it may not be possible, when, for instance, there are other people in the room who would be disturbed or when it would wake a sleeping child. Sometimes we make it not possible because of embarrassment. There may be times when we cannot legitimately call upon God with our voices. But it is worth the work to find quiet places where one can call out to God with an audible voice.
Praying out loud does not enable God to hear you better. God knows the secret intents of the heart. He knows your thoughts from afar (Psalm 139:1-4). But it will help you. Giving voice to your prayers will enable you to remain focussed better than if you only pray internally with your thoughts. Even if all you can do is whisper, at least you are “giving voice” to the thoughts that well up from within that you need to express to the loving Father you call upon.
Praying aloud is also particularly helpful when things are going badly. It is a release. It is an expression of genuineness that the stress you are under demands to make.
We all complain at some point of not having someone to talk to. God is not a flesh and blood person who we can see and feel with the touch (and God provides those as well). But He is real and He is present and not to talk aloud to Him just seems a little bizarre. Praying aloud is an indication of real concern and real pain.
Prayer is a form of worship whether it is calling out to God with shouts of praise or agonizing over the souls of our loved ones. And we are encouraged by the Scriptures to worship with all our hearts with an audible voice. This is in part for the sake of others, so that they can hear us, but it is helpful to you even when you do it alone.
In Psalm 142 David tells us that when he is need of God’s help he calls out with his voice. When he has a complaint about the way that things are going he tells God out loud. He gives the details of his troubles to God by speaking to Him. He talks to God aloud about God’s abilities to deliver. He calls upon God to discover what is happening to him. David knows that God already knows. God knows everything. It is no more strange for us to tell God what our news is than it is to ask Him for help. He knows what our needs are.
Prayer is not about giving God information. It is about expressing faith. It is about showing where our hope is. It is about using a tool that God has ordained to work through. And my suggestion is that this, and more, is better for us and enables us to utilize it better if we do it out loud, whether we are with others or not.
It is doubtful that if there are people who do not pray aloud whether they pray very much at all. Show that you really believe that God is there in the room with you – talk to Him like you would talk to anyone. Express yourself, with words, out loud, to the One who is there to hear you and answer your requests.