Voice problems

The third person in about a week has just told me they can't hear me on the phone. I know volume when speaking becomes a problem, but I still sound normal to myself. Does anyone know if you still hear yourself at full volume when others think you are whispering.
Yep. I have been told I speak very softly. Even though I think my voice is normal volume. I try to speak louder but feel as though I am shouting at people.
Thanks Christo. My daughter is coming at the weekend, when I have her opinion of how I sound maybe I'll ask the PD nurse about speech therapy