Recognition of warning signals in a working environment

Researcher(s): M.M. Scharloo-Cressent, MSc.
Supervisor(s): prof. W.A. Dreschler, PhD.

Background:
For auditory functioning at the workplace, warning signals are sometimes of the utmost importance. Examples of these signals are:

The beeps made by a van, when driving backwards
An alarm signalling a motor band failure at a plant
The different warning signals in hospitals

Hearing loss, whether it is noise induced or not, will not only result in a threshold shift, but also in a reduced discrimination of sounds. Therefore, additional testing may be required to diagnose a person’s auditory capacities.

Aim:
A new test has been developed in order to diagnose if there are problems to be expected in detecting and recognizing warning signals by hearing-impaired persons, in a working environment.

Method:
The test consists of three parts. First a threshold measurement, second a training and third the recognition measurement. In background noise an artificial signal, sounding like an auto alarm, has to be recognized amongst other artificial signals (called distracters). The distracters are made more alike the target signal until the test person cannot differ between target and distracter. The distraction signals are changed in 6 dimensions and by means of 6 independent interleaved up/down procedures. For each of these dimensions the discrimination threshold is determined. Thus, the procedure gives six JND (Just Noticeable Difference) values which can be compared to the mean values of normal hearing persons.

Results:
Norm data has been gathered on twelve normal hearing subjects. Three out the six dimensions appeared to be significantly correlated. In a second version of the test, the procedures will be shortened by using only the three most discriminating dimensions.

Future research:
Data will be collected from hearing impaired subjects that have to discriminate warning signals in their work. Their results will be compared to the data from the normal hearing subjects.


Home Onderwijs Wetenschap Research (EN)
General Otology Prevention of hearing loss Auditory profile Rehabilitation Hearing at work Auditory demands at work Recognition of warning signals Publications Presentations	Recognition of warning signals in a working environment Researcher(s): M.M. Scharloo-Cressent, MSc. Supervisor(s): prof. W.A. Dreschler, PhD. Background: For auditory functioning at the workplace, warning signals are sometimes of the utmost importance. Examples of these signals are: The beeps made by a van, when driving backwards An alarm signalling a motor band failure at a plant The different warning signals in hospitals Hearing loss, whether it is noise induced or not, will not only result in a threshold shift, but also in a reduced discrimination of sounds. Therefore, additional testing may be required to diagnose a person’s auditory capacities. Aim: A new test has been developed in order to diagnose if there are problems to be expected in detecting and recognizing warning signals by hearing-impaired persons, in a working environment. Method: The test consists of three parts. First a threshold measurement, second a training and third the recognition measurement. In background noise an artificial signal, sounding like an auto alarm, has to be recognized amongst other artificial signals (called distracters). The distracters are made more alike the target signal until the test person cannot differ between target and distracter. The distraction signals are changed in 6 dimensions and by means of 6 independent interleaved up/down procedures. For each of these dimensions the discrimination threshold is determined. Thus, the procedure gives six JND (Just Noticeable Difference) values which can be compared to the mean values of normal hearing persons. Results: Norm data has been gathered on twelve normal hearing subjects. Three out the six dimensions appeared to be significantly correlated. In a second version of the test, the procedures will be shortened by using only the three most discriminating dimensions. Future research: Data will be collected from hearing impaired subjects that have to discriminate warning signals in their work. Their results will be compared to the data from the normal hearing subjects.