- 1-year practical experience of below ground work in mines;
- 2 years practical experience of below ground work in mines;
- 5 years practical experience of below ground work in mines;
- 4 years practical experience of below ground work in mines;
- 3 years practical experience of below ground work in mines;
- 120 dB (A)
- 130 dB (A)
- 140 dB (A)
- 115 dB (A)
- 90 dB (A)
- 85 dB (A)