Was this the off hook tone for telephone 5PH Switches

Was this the off hook tone for telephone 5PH Switches? It said in another site that ATT/Philps Tel 5ESS-PBX Host was 5PH to. So did they have this off hook tone? I still wanna know what kind of off hook tone this is and what the technical name for this off hook tone is. Please let me know. Thank you.