What causes hydraulic pump whine?

Related questions

1. Why do we use hydraulics?
2. What are the advantages of hydraulics?
3. What is meant by hydraulic pressure?
4. What is a hydraulic shuttle valve?
5. Do cranes use hydraulics?
6. What causes hydraulic pressure?
7. How does hydraulic bridge work?
8. How does a 2 stage hydraulic pump work?
9. What do Hydraulics do?
10. Is hydraulic jack oil the same as hydraulic oil?

Tags

1. #change
2. #changes
3. #atmospheric
4. #fluid
5. #result
6. #suction
7. #pressure
8. #occur
9. #cavitation
10. #machine
11. #somewhat
12. #hydraulic
13. #coming
14. #sound
15. #distinguished
16. #whining
17. #surrounding
18. #erratic
19. #below
20. #therefore