So I purchased a few of these units for a client of mine and setup an Asterisk appliance to act as a PBX. I got everything all squared away, but the president of the company I am doing work for has a hearing problem, and is having problems hearing the speakerphone. I have cranked up the speaker volume, I set the speaker volume to 15 on the phone's firmware, and I also updated the firmware to the latest version. The speaker is still not loud enough for the guy. I was wondering if there are any external speaker/microphone units for the 2.5mm jack on the phone, or if anyone has any suggestions for an IP/SIP based phone that has a loud speaker, that won't cost me $600+.