I have 3 M7310 phone in a restaurant that is very noisy. The staff is complaining that the volume is too low on the phones to hear. I have explained to them how to turn the volume up on the phones. Is there a way to keep the volume on high? It seems to default middle way every session. Does the CICS system allow for this? I either need to switch the KSU with one that will allow for the volume to be saved or use a handset amp. Does anyone have any suggestions? Thanks for any help.