What is a Standard Threshold Shift (STS)?
What is a Standard Threshold Shift (STS)?
Comparisons of baseline and year to year hearing tests results (also called audiograms), is referred to as a standard threshold shift (STS). A standard threshold shift is a method to compare or measure changes to an individuals hearing levels over a period of time. An STS is an average shift in either ear of 10 dB or more at 2,000, 3,000, and 4,000 hertz. Age corrections are applied in determining STS.
OSHA requires employees exposed to loud noise as a part of their job undergo baseline and annual audiograms to determine hearing thresholds. Most, but not all screening audiometers have an automatic STS reporting function to allow for tracking hearing threshold level changes.