Good quality speaker/ conference phone

[SJL]

I am looking for a really good quality conference or speaker phone. I have spent hours searching the web but the reviews for most of them say that the receiver of the call often loses sound. I am trying to find a phone for a disabled person who is unable to use a headset who already has a phone with this problem. I speak to her daily and it is a nightmare as I can't hear half of what she says.

I would really appreciate any recommendations. Thank you.