Step by step tones after finishing a call for telephone switch type ATT/Philps Tel 5ESS-PBX Host

This is the step by step tones after finishing a call for Telephone Switch type ATT/Philps Tel 5ESS-PBX host. The first tone is the same but the off hook tone at the end is different. I still wanna know what kind of off hook tone this is and what the technical name for this off hook tone. Please let me know. Thank you.