Case Studies

These case studies illustrate how Alcoa is acting upon its commitment to sustainable development throughout the world. We are pleased with this progress, but look forward to achieving even more.

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Intalco employee wearing the advanced hearing-protection device.
Intalco employee wearing the advanced hearing-protection device.


USA - 2011

Advanced Technology Reduces Hearing Loss in Smelter Employees


To address occupationally related hearing loss among employees, Alcoa’s Intalco Works smelter in Ferndale, Washington (USA), implemented an advanced hearing protection program that helped reduce hearing loss cases to zero every year starting in 2008.


Employees participating in the DoseBusters program work in areas where hearing protection is required and they are either at risk of having an occupationally related hearing loss or have already experienced one. Prior to the program, the effectiveness of traditional personal hearing protection (earplugs or earmuffs ) relied on the assumptions that employees could achieve a perfect fit every time they put on hearing protection and that noise levels in the workplace never changed.


In the DoseBusters program, employees use technology that monitors the actual noise levels inside their ear canals. Each of the earplugs or earmuffs worn by an employee contains a microphone that is attached via wires to an electronic device about the size of a deck of playing cards. The device takes 10 noise-exposure readings per second in both microphones, taking into account the exposure with the highest reading. Once an employee hits a pre-determined exposure limit, a light on the device turns on to alert the employee to the situation.


At any time during the day, an employee can download the data collected by the device to get an instant exposure reading. All employees are required to download their data into the monitoring system at the end of their shift. If any overexposures are detected, the system automatically sends an email to an employee’s supervisor, who is required to address the issue with the employee immediately.


Jerry Lentz, Intalco’s casthouse maintenance supervisor and an early participant in the program, had initial reservations about the technology but is now a convert.


“The device gives me an awareness of when and where I have exposures to elevated noise conditions, and I take the time to put on extra protection in those areas,” said Lentz. “When I see someone without hearing protection today, I get them engaged. I’m such an advocate of the program that I think everyone should be able to participate, even if they are not currently at risk for hearing loss. Having this knowledge earlier in one’s career would be very advantageous.”


Due to the success at Intalco, several other Alcoa plants have implemented the program under the QuietDose name.