Custom fit hearing check

Alcoa has enhanced its existing Hearing Conservation and Protection Program by introducing technology that accurately tests the attenuation of an individual’s hearing protection device.

Alcoa has enhanced its existing Hearing Conservation and Protection Program by introducing technology that accurately tests the attenuation of an individual’s hearing protection device.

The technology has initiated a new approach to hearing preservation by custom fitting hearing protection to each individual through one-on-one consultations, targeted training and closer monitoring.

This personalised process allows the company’s occupational hygiene team to take corrective action faster, reducing the risk of noise-induced hearing loss across every site in Western Australia.

The challenge

As part of its commitment to ensuring the highest level of hearing protection practicable, Alcoa’s team of occupational hygienists selected a range of industry standard ear protection for their employees and then actively promoted specific types of ear plugs offering the highest level of attenuation.

These ear plugs were widely accepted as the ear protection of choice by the majority of the workforce. In addition to this, training sessions on the effective use of the full range of hearing protection devices (e.g. ear plugs, ear muffs) were delivered through group sessions at each of the company’s sites.

The selection of a hearing protection device was then left to each individual.

Following these initiatives, annual audiogram tests revealed that, in some cases, the preferred ear plug did not sufficiently protect against noise exposure for all employees.

The company was determined to find out the reason why the preferred hearing protection was not performing and then communicate a change in strategy to their 2,500 strong workforce across six different sites.

The solution

The company trialled a new testing process using a software system that measures the level of attenuation achieved by the ear plug hearing protection for each individual within a small sample group located at Wagerup.

The system plays a series of nine different sounds, each with a varying pitch or frequency, through earphones.

The sounds begin at a higher frequency and the individual releases a button when the sound becomes inaudible.

When the frequencies gradually begin to increase, the individual activates the button when they can again detect a sound.

The system measures the difference between these two points to provide a pass or fail score for the hearing device by averaging the decibels logarithmically.

The pass and fail marks are standard for all employees, so that they can safely move between different areas on site if required.

If the individual fails the test with the hearing protection correctly inserted, the occupational hygienist will suggest a different type and style of ear plug that is comfortable for the individual and brings the individual to the rated attenuation.

In addition to this, the one-on-one consultation provides an opportunity for the occupational hygienist to observe the way in which the individual inserts the ear plug, ensuring use of the correct technique.

The Wagerup sample group reported that the technology and one-on-one consultation process helped to correctly identify an improved type of hearing protection that was more comfortable and reduced noise exposure in their working environment.

The technology is now deployed across all of the company’s sites, with a new supporting procedure and promotions program to encourage a change in behaviour in the way hearing protection was selected and used.

The results

Alcoa has successfully reduced the number of employees who were experiencing sensory threshold shifts from exposure to noise levels by individualising the way hearing protection devices are allocated to each employee.

The technology, and its supporting processes, has allowed the company’s occupational hygiene team to target employees who are at risk of noise-induced hearing loss, and through one-on-one consultations, provided a way to assess whether hearing protection is effective and make immediate adjustments if required.

This process also provides a documented measurement of a successful fit for each employee, rather than depending on an estimation based on the labelling of the hearing protection device.

Once the correct hearing protection is identified, a sticker applied to the employee’s safety helmet reminds the employee of the type of plug suited to them and aids easy identification when group leaders conduct compliance audits.

The technology is PC-based and portable, allowing individual fit testing to be easily deployed and conducted across each site, successfully enhancing the company’s Hearing Conservation and Protection Program.

The company now has a personal snapshot of how well a type of hearing protection is performing through a test method that is ear-specific, user-specific and product-specific.

*This article was first published in The Chamber of Minerals and Energy Western Australias First Watch newsletter.

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