Download the most current version of the TWA Calculator User Guide
TWA Calculator User Guide Version 2.1 (430 KB) 
If your TWA Calculator Import Template file becomes lost or corrupted, you can download a fresh copy here:
TWA Calculator Import Template (830 KB) 
Looking for Noise Data to Use in TWA Calculator?
Find sound levels associated with occupational and non-occupational noise exposures and equipment noise emissions to use in creating noise exposure scenario cases in the EAR Noise Navigator® Sound Level Database 
(883 KB) or any of these online noise emission databases.
Share Your Noise Exposure Scenarios
Do you have cases you use to illustrate noise exposure and dose concepts in a teaching environment? Share them with other TWA Calculator users by contributing to a library of example noise exposure scenario cases. Submit the pertinent data (and any key teaching points) for each case using our contact form. Contributed examples will be used to create a downloadable file of example scenarios. Examples could illustrate any of the following concepts, as well as the obvious relationships between duration, level and dose:
- Typical occupational noise exposure scenarios for various jobs
- Effects of measurement sound level threshold on calculations
- Workshifts longer than 8 hours
- OSHA vs. NIOSH comparisons
- Effect of rounding scheme on decision-making