Are you referring to Austin/Travis County EMS? They are on GATRRS. ATCEMS has a broadcastify feed that you can listen in on. Austin FD/Travis County ESDs used to have one but the feed manager moved out of the area.
I tried to contact the feed manager that had the FD Travis county before he moved, because I was trying to set up the feed once he left. I listen to the EMS channel on broadcastify, but it doesn't have near the traffic that the FD had.
You can hear some fire Dispatch on 154.205 and 154.965 and 154.175 you can also listen online to EMS here: Broadcastify Mobile Feed Details
Williamson County EMS dispatch only 462.975