disability phone dialler

[boots_n_braces]

Hi guys,

Im after some close to home help on an area that i know nothing about! my grans blind and currently has a phone with voice dialling i.e you speak the name of the person you wish to call (names and numbers pre recorded) and it calls them. Unfortunatley like most things voice recognition its not very good and shes struggling! The voice recognition is an interupter box that sits in the phone line between wall jack and the phone.

Im thinking about flipping the theory on its head and having a similar interrupter box with a big button and pressing it cycles through a list of contacts with the phone reading out the names and a second large button to confirm the call.

However i know nothing about telecomms, dial tone etc etc so any help would be gratefull from links to tutorials to a full schematic. Im busy learning everything i can but the faster i can get this sorted the better.

 

[boots_n_braces]

Ok ive found a simple voice synthesiser ic and a fairly simple interfacable dial tone generator so the basics are off to a good start:-D

Can anyone help on interfacing to the phone line its self? required isolation etc

Thanks
harry

 

[tpetar]

Use transformer 600:600 600R impedance. Remove this transformer from some old dialup modem.