If one is davening b'yichidut (praying by oneself), without a minyan, do they need to say the amidah silently or can they say it out loud?
Phrased another way, what is the reason for praying the amidah silently when praying with a minyan? Is it so as not to disturb other people who are also praying, or is there another reason that would no longer apply when one is not praying with a minyan?