Related Experiment Video
Updated: Aug 16, 2026

Neuro-rehabilitation Approach for Sudden Sensorineural Hearing Loss
Published on: January 26, 2016
[Normal hearing, loss of hearing and general occupational disability]
1Istituto di Audiologia e Fonologia dell'Università di Torino.
Abstract:
A real, practical definition of normal hearing is an absolutely indispensable yardstick by which to measure the degree of general occupational disability attributed to reduced auditory capacity. If progressive impairment of the organ of Corti, due to age and non-occupational noise factors is also taken into account, a practical borderline between normal and reduced hearing can be defined as a mean bilateral threshold level for air conduction higher than 25 dB for the usual conversational frequencies, as per D.P.R. 1124/1965 and in accordance with ISO R/389/1964 and ANSI/1969. Suggestions are also put forward for the definition of general occupational disability.
More Related Videos
Related Concept Videos
Hearing
Perception of Sound Waves
The pitch of a sound depends on the frequency and the pressure amplitude of the source. Two sounds of the same frequency...
Sound Intensity Level
The human ear can perceive an extensive range of sound intensity, necessitating the use of the logarithmic scale to define a physical quantity—the intensity level. It is a ratio of two intensities and hence a...
Unrenewable Cells
Photoreceptors
The retina is composed of several layers and contains specialized cells called photoreceptors. The photoreceptors (rods and cones) change their membrane potential when stimulated by light energy. There are two types of photoreceptors—rods and cones—which differ in the shape of their outer...

