"Pondering out loud" is not to common, but would be the same as "thinking out loud". This means that some is expressing his thoughts without actually speaking directly to someone in particular. Someone might say, "What did you say?", and you answer, "Nothing! I'm just thinking out loud".

It means to be 'thinking out loud'

ponder= to think deeply another popular phrase is, thinking out loud. Both mean the same, to speak whatever you are thinking or whatever is in your mind. Suppose, 3 friends are trying to solve something together. Am idea comes to one of them. He says, I was thinking it may be solved if we try this ....... That is called pondering out loud. Hope this helps. :)

any speaking partner

thx for reminding me :D