General Facts About Hearing Loss
What is a Temporary Hearing Loss (Temporary Threshold Shift)?
With a temporary hearing loss, normal hearing will usually return after a rest period away from all sources of intense or loud noise. The recovery period may be minutes, hours, a day or perhaps even longer. It is believed that a temporary hearing loss occurs when hair cells in the inner ear have been bent by vibrations and need time to bounce back, or when the fluid in the inner ear has changed chemically because of over-stimulations, and needs time to revert to its original composition.
What is a Permanent Hearing Loss (Permanent Threshold Shift)?
A permanent hearing loss is the result of hair cells or nerve destruction within the cochlea. Once these important parts of the hearing process are destroyed, they can never be restored or regenerated. The resulting permanent hearing loss, also referred to as permanent threshold shift (PTS), can range from slight to total hearing loss.
The following factors determine the degree and extent of hearing loss:
- Type of Noise – continuous, intermittent, impact, high or low frequency
- Intensity of Noise – level of loudness
- Duration of Exposure – length of time subjected to noise, and over time how often subjected to noise
- Type of Noise Environment – enclosed, open, reflective surfaces
- Distance from Ears to the Source of Noise – earphones in the ear, centimeters from the ear, meters, etc.
- Physical position/posture relative to the noise source
- Age of listener
- Individual Susceptibility
- General Health of listener
- Number of other Exposures to Noise – at home, in the workplace, during recreational/leisure activities, etc.
