ok i will be happy to give you more details about this one try concant this company is harris commuacations the web address is
www.harriscomm.com and the other company is
www.barrproductions.com i am sure both of them will help you with the system you need and i am hard of hearing myself so i know how it is btw most of them use wiresless devices and i have wireless device in my home it work good ( it have flashing strobe light )it work both doorbell and telephone system. it will flash 2 diffrent rates to indentify it
if any more question please do post it here and i will be more than happy to reply it
merci marc
