Audiometric Testing

Mobile, Convenient, Affordable

 Hearing is tested by checking a person’s response to pure tone sounds in frequencies that span the major range of human hearing (250 – 8000 Hz).  The first test given to an employee is considered a ‘baseline’.  This is what future hearing ability is compared to for the purposes of quantifying hearing loss. Mobile hearing testing is just one part of our complete Hearing Conservation program that includes noise surveys, education and testing.

Our Hearing Conservation programs include:

• Noise surveys
• Audiometric Testing
• Employee education on hearing loss
• Customized reporting package
• Individualized hearing test report letters
• Consultation for Engineering Controls
• Consultation for Administrative Best Practices
• Recomendations for PPE

Although there are several ways that people may suffer hearing loss, the most common type in industry is a cumulative loss due to long-term exposure to noise levels consistently in excess of 85 dBA in the workplace.  This repeated exposure to noise causes a temporary hearing loss and eventually leads to a permanent noise induced hearing loss (NIHL).

In order understand audiometric results and the associated liabilities there are several terms associated with hearing loss that are important to defined:

Temporary Threshold Shift (TTS)

Temporary hearing loss occurs when hair cells in the inner ear have been damaged by excessive sound.  This is typically noticeable by a ‘ringing in the ears’ (tinnitus).  This typically occurs during short term exposures to high noise levels, for example at a loud concert.  If a person’s hearing was assessed immediately after this exposure, the test would show a decrease in hearing ability.  If the hearing ability returns to normal (baseline levels) after a short period of time, the shift in hearing ability is considered to be temporary, thus a Temporary Threshold Shift (TTS).
Even though the temporary loss may go away, permanent damage may have occurred in the ear and continued exposure to high noise levels may result in a permanent hearing loss.

Standard (or Significant) Threshold Shift (STS)

Standard Threshold Shift is a term defined by OSHA (US) [1910.95(g)(10)(i)] to describe a change in hearing threshold relative to the baseline audiogram of an average of 10 dB or more at 2000, 3000 and 4000 Hz in either ear from baseline levels.  Under OSHA regulations, additional audiometric testing and follow-up is required when an employee is found to have an STS.  NIOSH also uses this term to describe a change of 15 dB or more at any frequency, 500 through 6000 Hz, from baseline levels in the same ear and at the same frequency.

Permanent (or Persistent) Threshold Shift (PTS)

A Permanent Threshold Shift (PTS) refers to the damage to the ear as a result of continued or repeated exposure to excessive noise over a period of time.  When Temporary of Standard Threshold Shifts are shown to be persistent and no recovery of hearing ability occurs, a person is said to have suffered a permanent hearing loss.