Cotral Hearing Protection - Frequently Asked Questions

Cotral Lab is built around three themes: protect, raise awareness, and validate. Find the most frequently asked questions and our answers here.

Your questions on hearing protection devices:

Hearing aids are instruments that amplify sound. They are used when people already suffer from hearing loss. Hearing protection devices, such as Cotral custom moulded earplugs, on the other hand, are made to prevent hearing loss.

Qeos moulded earplugs meet the main requirements of the food-processing industry: a detectable ball and cord can be offered as an option. For better visibility, Qeos custom moulded earplugs are blue.

Your Hearing Prevention Specialist will select the filters and the hearing protection type, using the SAPAN method. After questioning the user, the application proposes a list of hearing protection devices that are suitable for each person, so that the employee is protected from noise without being isolated.

SNR is the acronym for Single Number Rating. It is the global index of impairment, a weighted average of impairment on all measured frequencies (63, 125, 250, 500, 1000, 2000, 4000, and 8000 Hz).

Cotral guarantees all its hearing protection devices for a period of 6 years. Beyond that, we advise you to take a new set of impressions or assess their real efficiency with a CAPA test.

You will benefit from a unique guarantee in the hearing protection device market: the Effi-6 Guarantee. It covers product manufacture, as well as comfort. Your hearing protection is offered with a money-back guarantee.

There are two types of filters, both of which reduce noise differently:

  • Flat response filters reduce sound without distorting it. Imagine being able to reduce the ambient volume, just as you do with your MP3 player or your Stereo system. These filters offer the same sound quality, with reduced volume. These hearing protection devices are equipped with filters that are recommended for technicians who must listen to the slightest malfunction, people who have to communicate in a noisy environment.
  • HFA (High Frequency Attenuation) filters soften noises on high frequencies. These filters are useful in very noisy industries: food-processing, metallurgy, construction industry, etc.

Using your Filter Box, by following SAPAN recommendations, you will be able to autonomously change your filters and manipulate the attenuation of your protective hearing devices. Please refer to your product information leaflet that can be found in the Filter Box.

You can also call Customer Service or your Hearing Prevention Specialist who will adjust the attenuation by changing the filters.

The Filter Box is a box set that contains several pairs of acoustic filters. It allows you to autonomously manipulate the attenuation of your employees' Cotral moulded earplugs. Based on the hearing protection device model you are using, you can choose the Filter Box that suits you:

  • Filter Box OS for Qeos Green
  • Filter Box XT for Qeos Orange

Wearing hearing protection devices is an important factor that guarantees their efficiency. The best hearing protection is the one that is worn 100% of the time. If the device is not worn, even for a short period of time, its efficiency reduces rapidly. If the device is not worn for 2 minutes in an 8-hour working day at 80 dB(A), its efficiency is reduced by 25%. Here are the conditions that must be met to ensure that your employees wear their hearing protection devices 100% of the time spent in a noisy environment:

  1. Using comfortable hearing protection devices
  2. Adapting the device to each person’s work environment
  3. Being aware of noise-related risks
  4. Selecting hearing protection devices that are easy to use and clean

To replace a lost hearing protection device, get in touch with Customer Service at Click on “Your online assistance”, then “Request for assistance”. While you wait for your new moulded earplugs, you must provide alternative hearing protection to your employees.

Your employee has been provided with custom moulded ear plugs. He is thus the only one who can use them.

The first thing to do after distributing the custom moulded earplugs to your employees is to remind them of the importance of wearing them gradually. Even when the moulded ear plugs fit perfectly in the ears, they are still not a part of the body. Wearing them can be troublesome for your employees. It is therefore recommended to wear them regularly, but gradually: 2 hours during their shift for the first few days, and then gradually increase the duration. It takes two to three weeks to fully adapt.

When wearing their protectors for the first time, your employees could experience the following effects:

  • An internal resonance
  • The feeling of being in a soundproof box
  • An irritation in the ears
  • The impression that voices are too loud or the noise of machines is too low

Such sensations are perfectly normal. They do not last and disappear with time if your employees follow the adaptation recommendations.

Occupational Noise-Induced Hearing Loss (ONIHL) is a perceptive deafness that is caused by exposure to noise in the workplace. It is characterised by a reduction in hearing acuity: the transmission of sound is correct, but its perception is defective. It corresponds to the destruction of ciliated cells.

If the deafness is identified as an occupational disease, the organization is responsible.

In terms of safety and prevention, the employer has an obligation to achieve a result. If an employee is diagnosed with ONIHL due to their professional activity, but the employer provides him with equipment for prevention and protection, the law will take into account all of these elements.

In cases where noise intensity limits have been exceeded, it is possible to increase noise reduction with double protection. This is composed of an intra-ear plug (standard or custom) and shell-shaped headband.

How is the noise reduction of double protection calculated?
The formula is as follows: 33 x log ((0.4 x reduction of intra) + (0.1 x reduction of ear muffs)) (Etude A. Damongeot et al.)
Example: A moulded earplug with an attenuation level of 32 dB and an ear muff with an attenuation level of 35 dB = 40 dB attenuation.

A noise-cancelling earplug is not more efficient. If an employee is exposed to a noise level of 85 dB(A), equipping him with an Individual Noise Protector with an attenuation level of 30 dB would be a mistake. If workers are too isolated, they will not tolerate their hearing protection devices. Your employees will be tempted to remove them in order to listen to warning signals or communicate with one another. The EN-458 norm recommends a threshold level between 70 and 75 dB(A). The objective is to reduce the perceived noise levels under 75 dB(A).

The cost can vary, depending on several factors. The amount may seem to be higher when compared to standard disposable earplugs, but if you compare overall spending over 6 years, you will see that Cotral Lab's complete solution is more economical.

Cotral Lab's Hearing Conservation Technician comes to your site to take your employees’ ear impressions. This meeting enables an exchange of information on the risks related to noise and the usage of Cotral moulded earplugs. Cotral experts use the SAPAN method to determine which hearing protection device is most suitable for each employee, based on their specifics and the nature of their work. Everything is configured with respect to the functioning of your organisation.

Your questions about raising awareness among your employees:

When you train your employees on noise-related risks, you make them responsible and conscious of the fact that they are exposing themselves to an invisible danger every day. They become responsible for their own hearing health and adopt proper behaviours: wearing their hearing protection devices constantly during exposure, not taking them off while communicating, and so on. If hearing protection devices are properly worn, the risk of noise-induced hearing loss is reduced.

Simple suggestions that will ensure a successful hearing conservation program:

  1. Plan numerous campaigns throughout the year
  2. Multiply channels of communication for greater impact: videos, comics, games, posters, and so on
  3. Repeat your messages regularly

Your questions on how to validate the efficiency of hearing protection devices:

Use CAPA© to determine whether your employees' hearing protectors are still reducing noise effectively after years of use. It validates whether the intra-ear hearing protection devices:

  1. Comply with manufacturer specifications
  2. Efficiently protect employees

Cotral Laboratory offers 3 possibilities for conducting efficiency tests:

  • Buy the software and equipment to conduct the tests in full autonomy
  • Borrow the software and equipment to conduct the tests for a limited period
  • Choose the full service option provided by Hearing Prevention Specialist at your organisation's

Several scientific studies have established that the external ear grows throughout life. The custom moulded earplug is generally a replica:

  • Of a part of the auditory canal
  • Of a part or even the totality of the earlobe
  • Of the ear hook, sometimes

No study has yet established that ear growth has an impact on the ear canal. As a result, Cotral Lab recommends testing custom moulded earplugs devices at the end of the guarantee period. If they are still efficient, your employees can continue using them to ensure their hearing health. However, if the test reveals that hearing protection devices do not reduce noise as much as they used to, you must renew the devices.