What Does Standard Threshold Shift (STS) Mean?
Standard Threshold Shift (STS) is a significant change in the hearing ability of a person in one or both ears of an average of 10 decibels (dB) or more at 2000, 3000, and 4000 hertz (Hz). STS is defined in the occupational noise exposure standard at 29 CFR 1910.95(g)(10)(i).
Safeopedia Explains Standard Threshold Shift (STS)
Loud noise can lead to hearing loss. When working in high-level noise, ear protection is key. As per a report from the National Institute for Occupational Safety and Health (NIOSH), there are nearly 22 million workers in the United States who had to work in high-level hazardous noise, and approximately $242 million in compensation has been paid for hearing loss disability every year. That is why hearing loss is the most common occupational illness in the U.S.
There are different types of Hearing Protection Devices (HPDs) available such as earmuffs and earplugs. According to WMA, it has become necessary to use earplugs and earmuffs in high-decibel-producing areas to avoid STS and in turn protect the ears from hearing loss.
Earmuffs are a very stylish ear protection device typically designed for both ears with a headband. They are made of a high-quality, sound-absorbing material like foam. Earplugs are also a stylish HPD, and they're designed to fit in your ear canal. There are many kinds of earplugs available, which are detailed below:
- Pre-molded Earplugs: These come with a push-to-fit design to protect the ears from many industrial noises.
- Formable Earplugs: These are designed for the individual ear canals.
- Roll-down Foam Earplugs: These are the most commonly used earplugs in the U.S., and they're made from slow-recovery foam. Just roll them down and insert them into the ear canal. This will create a sound-tight cover for the ears.
- Custom Earplugs: These are typically custom-designed ear protectors that can be purchased only from an audiology clinic or hearing healthcare professional.
- Electronic Hearing Protection Devices: This kind of HPD can reduce industrial noise through a combination of electronic and structural components. Available in both the earmuff or earplug style, this type of HPD is also known as a noise-canceling device.
- Canal Cap: This looks similar to earplugs, but both caps are connected by a band to keep them in position.
- Dual Hearing Protection: This is a combination of both earplugs and earmuffs. Generally, people use this device to work in high-level noise areas like the mining industry. It has an advanced technology that allows the user to talk with others by making human speech clearer. It is also beneficial for those who already have some hearing loss.