How does an intercom work?

Related questions

1. How do PRI lines work?
2. What is intercom app?
3. What's the difference between PRI and SIP?
4. What is e1 in telecom?
5. What is intercom used for?
6. How much is a home intercom system?
7. What is PRI and SIP?
8. How can I ring my own landline?
9. Do I need a special phone for VoIP?
10. How do wireless intercom systems work?

Tags

1. #different
2. #speaking
3. #audio
4. #receiving
5. #people
6. #purpose
7. #communication
8. #person
9. #electronic
10. #video
11. #transmissions
12. #speaker
13. #circuitry
14. #contains
15. #microphone
16. #device
17. #transmitting
18. #allows
19. #intercom
20. #heard