AGS Cookbook - Hearing examination 1

Hearing examination
Oscilla AudioConsole

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Background:

Sound occurs when molecules in the air are put into oscillations (vibrations). The number of oscillations per second is called the frequency of the tone and is measured in Hertz (Hz).

Deep tones have low frequencies, and bright tones have high frequencies. The range between 20 Hz and 20,000 Hz is called the audible range. However, the term is a bit misleading, as many can hear frequencies below 20 Hz, while few can hear frequencies up to 20,000 Hz.

The more energy a sound has, the louder it acts on us. The unit decibel – abbreviated dB, is used, so that the volume can also be measured, and thereby expressed as noise. The loudness is a logarithmic scale and the loudness doubles for every 3 dB. The double of 80 dB sound pressure is thus 83 dB.
This is the parameter that the legislation is about.

In the case of hearing loss with high-frequency sounds, it is initially only the high frequencies that the person hears poorly. These include hissing sounds (-s-, -f- or -sh-) and consonants. Tones with high frequencies, such as a doorbell, a telephone or children’s voices, hear the affected people poorly.
With advanced hearing loss, it also becomes more difficult to perceive low frequencies.

This YOUTUBE clip explains the reading of an Audiogram from a hearing examination. Our graduations are a little more “restrictive”, but it is so brilliantly explained which symptoms you can be aware of:

The legal requirement:

The hearing examination is a screening examination that identifies hearing loss, possibly based on noise. Clients with hearing loss are recommended further investigation by an ear doctor, who ensures any reporting to the National Board of Industrial Injuries.

Employees who are exposed to noise exposure in connection with their work must, according to current legislation, be offered a Hearing examination and for particularly stressful noise exposure – also an occupational medical examination with a focus on noise exposure (not offered by AGS).

The legal basis for noise above 85 dB is AT Executive Order no. 63, February 2006 and AT Executive Order no. 1165, December 1992 (Executive Order on Occupational Medical Examinations), as well as AT Guidelines D.6.1-4 item 10:

§ 15. Employees who are exposed to noise that exceeds a noise exposure of 80 dB(A) or peak values of pulses of 135 dB(C) must have access to a Hearing Examination, including an audiometric examination, if the workplace assessment, cf. sections 4-7, shows risks as a result of noise.

The audiogram:

An audiogram has two axes.

On the vertical axis, volume is read, which is measured in decibels (dB). The further down the axis, the louder the volume of the tone. At the top of the axis is the lowest volume (0 dB). This tone can usually only just be heard.

On the horizontal axis, the tonal frequency is read, which is measured in hertz (Hz). The further to the right on the axis, the higher the frequency. This movement is very similar to a piano: the further to the right the key sits, the higher the frequency of the note. A normal conversation is in the frequency range between 500 and 3,000 Hz.

Results interpretations:

For interpretations of individual client measurements, the following tables are used in the clinic:

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Some rules of thumb/tips:

  • Hearing loss on the lower frequencies, and only in the left ear (if the client is right-handed), can indicate a hunting-related hearing impairment,
  • Hearing loss on the high frequencies in both ears indicates a work-related hearing impairment, or a music impairment,
  • If the client has normal hearing up to 4 kHz, it is usually hearing corresponding to age (remember to tick this off in ACCES) even if there is hearing loss on the frequencies after.
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Customer-specific Oscilla databases:

Since about 2020, we have chosen to perform and register hearing tests in database versions specifically for each customer.
However, this has the disadvantage that ON YOUR OWN PC you have to change the database link inside Oscilla – from project to project.

But it’s not as difficult as it may sound. It’s done like this- pictures will be coming soon ;) :

  1. Open Oscilla – select any client to arrive at the Hearing Test image.
  2. In the menu at the top left; Select FEATURES and SETTINGS.
  3. In the “pop-up” image, at the bottom right is a “explorer folder”. Click on this and you will see where the Oscilla databases are located.
  4. Select the Database that is current, e.g. ACDB TICAN, select Open.
  5. Click APPLY and OK in the pop-up window, which will then close.
  6. Oscilla now announces that it is necessary to restart Oscilla for the change to take effect.
  7. Close Oscilla – wait a few moments – Open Oscilla again. Now you should only see clients from that customer.
  8. Leave this setting as long as you are on this project.

Create new client:

  1. If the client has been here before, search in the yellow boxes above.
  2. If it is the client’s first time – then the client is created in the system. Remember that the surname column is used for ACCES no.
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New Audio session:

  1. Tool icon (outermost) → Automatic Hearing Test.
  2. If necessary, adjust the start sound level:
    • if it is a client who is familiar with hearing loss, then a lot of time is saved by setting the starting point to more than 5 dB.
    • If it is a young client who does not expect any hearing loss, start at 5 dB.
  3. The test is started on the “Gear”
  4. Data stored on disk icon at the top center.
  5. Print client report.
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ACCES data loading:

AGS-Klanen/03 Clinic databases;

STAND BY – WILL BE UPDATED Ref new Journal system.

Tip:
The list of previous tests in Oscilla tells how many times the client has been here before, and thus which visit number XX Form should be used.
If a client tells us that he/she was previously with another company that was also a customer of ours, please notify Peter – then the client’s tests can be moved over.

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Otoscopy:

In connection with a Hearing examination, an Otoscopy is performed.
We look for –

  • Unobstructed view of the eardrum,Damage
  • to the eardrum,Earwax
  • , bicycle frame, screwdrivers etc

. Ear shield is changed at each client, the same funnel may be used for both ears.
It is not unusual for a client to perform a poor hearing test if there is a lot of earwax, and in some cases the client is recommended to have an ear rinse done by the doctor.

Equipment: Wellch Allyn pocket Otoscope.

Health examination of women

Hearing protection:

In principle, AGS does not advise on the rules for, and the use of, hearing protection. The company’s occupational health and safety organisation must take care of this itself. We simply measure whether they can hear and how to prevent it from getting worse.
But that’s why you can know a little about it. And if you want to know more about hearing protection (than what is usually known), here is a good guide from the Danish Working Environment Authority with a number of definitions and explanations:

https://at.dk/regler/at-vejledninger/hoerevaern-d-5-2/#id-3-kravombugsni-2

Most interesting for our advice to clients is probably Item 5 (types of hearing protection) and Item 6 (Correct use of hearing protection).

It seems to be widely believed that “Noise-Cancelling” headsets remove the noise. This is a truth with modifications. Noise-Cancelling works by the headset listening to the noise and making a counter-noise, i.e. a sound with the same frequency and sound pressure but in a counter-phase, whereby the 2 noise sources cancel each other out. This can remove a constant sound, but is often not fast enough to neutralize sudden sounds.

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