How many Tennessee Telephone Company Inc. Offices were there in Tennessee with this off hook tone

How many Tennessee Telephone Company Inc. offices were in Tennessee with this off hook tone? Hard to believe there were several ATT/Philps Tel 5ESS-PBX Host at all Tennessee Telephone Company Inc. offices in Tennessee. So how many Tennessee Telephone Company Offices were there in Tennessee were there in Tennessee with this off hook tone? I still w3anna know what kind of off hook tone this was and what the technical name for this off hook tone was. Please let me know. Thank you.