- The training program includes a pre-learning phase that allows participants to familiarize themselves with foundational concepts before engaging in in-person interactions with the facilitator.
- Following the pre-learning phase, participants will have the opportunity to meet with the facilitator in a physical classroom setting. This direct interaction is crucial for addressing any questions or concerns that may have arisen during the self-study period.
- Additionally, the physical classroom component is designed to facilitate hands-on practical training. This aspect of the program allows participants to apply theoretical knowledge in real-world scenarios, enhancing their understanding and retention of the material. Working under the guidance of an experienced facilitator, learners can practice skills, collaborate with peers, and gain valuable insights that are difficult to achieve through online learning alone.
- Overall, this structured approach—combining pre-learning with direct facilitator contact and practical classroom experiences—ensures a comprehensive and effective learning journey that accommodates various learning styles and maximizes participant engagement.
Milestone Baseline or Audiometric Zero Copy
Milestone Baseline or Audiometric Zero
In the mining industry from 2015 the Standard Threshold Shift (STS) guidelines were implemented as outlined in Chapter 3 – Legislation. As a result of this guideline milestone baselines were done on all existing employees until 31 December 20178,5. Thereafter all new employees into the mining sector have a milestone baseline done to calculate the audiometric zero. This audiogram is used to calculate the STS which is used only for the early detection and prevention of NIHL8,5,6,7.
| Remember |
| A milestone baseline is performed the same way as a baseline audiogram. It is the better of the 2 tests conducted on the same day, same setting and 2 different sittings 10 minutes apart and should not differ by more than 10dB on any frequency5. |
To calculate the milestone, baseline the frequencies 2000, 3000 and 4000Hz are used (unlike in PLHS calculations), thereafter this result is used to compare future audiograms against to determine the STS. Certain interventions are required when the STS levels reach 10dB or equal to or greater than 25dB at any frequency8. This will be covered in Chapter 12.
How to calculate the Milestone Baseline or Audiometric Zero
Using table 10.7 below as the manual audiogram results:
This was a baseline done on Mr. C on the 14 September 2018This serves as the milestone baseline on Mr. C
The only numbers used for the audiometry zero are the frequencies 2000, 3000 and 4000Hz
Table 10.7: Numerical result of an audiogram
Using table 10.8 below as the manual audiogram results
This is the next audiogram done on Mr. C on the 14 March 2019Focus of the same frequencies 2000, 3000 and 4000Hz
Compare the decibel results of the 2 tests on the same frequencies in each ear separately
Compare table 10.7 results against table 10.8 results per ear and per frequency
Note the change in the results
subtract the current test from the audiometric zero result
Add the 3 results of the subtracted sum done above together
Take this total and divide it by 3 (because 3 frequencies are used)
This result is the STS = it is the average change in dBs on these 3 frequencies in that specific ear
Table 10.8: Numerical result of an audiogram
Recording these results
It is important to record the PLH, PLHS and STS results when performing the manual test after the calculations have been done. Write the BL PLH onto the audiogram and then include the PLHS from BL and from previous test if the is another test. If the BL was not done or is not valid remember to calculate the PLHS from 0. Ensure that the STS has calculated in the mining industry if the calculation is missing insert it manually.
An example of a manual audiogram depicting PLH / STS and PLHS
The PLH calculation
The STS Calculation
