The Center for Operator Performance (COP) has revealed research that indicates some alarm tones standard on Distributed Control Systems (DCS) may be undetectable by older operators who have age-induced hearing loss, and particularly so in the presence of control room noise. A pilot study by Dr. John Casali and Dr. Kichol Lee of Virginia Tech University conducted spectral analyses of alarm sounds in two refinery control rooms. Certain alarm sounds standard on DCS systems, like a chime, are predominately in the same frequency range that is affected by age-induced hearing loss.

According to COP, this means that older operators may be unable to “hear” alarms that use these sounds, which problematic if operators are able to adjust alarm volumes, where the previous shift operator may have reduced the volume, making detection more difficult.

Age-related hearing loss is an incredibly common and widespread issue across the globe. As we age, our hearing health may detiorate over time, resulting in presbycusis, also known as age-related hearing loss. Individuals with age-related hearing loss should seek treatment for their condition as soon as possible. This will allow them to preserve the hearing ability they have left and communicate with the world around them better.

A more detailed study to determine optimal alarm sounds is being planned. The study will provide recommendations not only to accommodate the age-induced and noise-induced hearing loss problems, but also encoding alarm priorities in multi-console control rooms.

About the Center for Operator Performance

The Center for Operator Performance is a diverse group of industry, vendor and academia representatives addressing human capabilities and limitations with research, collaboration and human factors engineering. The Center for Operator Performance understands the operational realities that operating safely requires redundancy of many components and operating competitively requires lack of redundancy of the human component. These complexities keep plant operators at the center of improving operational performance and at the center of our efforts bringing research insights into process plants.