No matter who you are, there’s always that one sound that makes your toes curl and your skin crawl. Whether it’s terracotta plant pots, nails on a chalkboard or children crying, there are a whole host of sounds out there that can only be described in one way: unbearable.
Is it just me, or can trying to decipher an OSHA regulation be confusing? Take, for instance, the OSHA Occupational Noise Exposure Standard (29 CFR 1910.95). The OSHA noise standard defines the action level to enroll an employee in a hearing conversation program as “an 8-hour time-weighted average of 85 decibels measured on the A-scale, slow response, or equivalently, a dose of 50 percent.” Because the action level is based on an exposure for an 8-hour work shift, a common point of confusion is what to do for work shifts that are not 8 hours, such as 10- or 12-hour work shifts. A common question we are asked is, “We work a 12-hour shift: Should I use 8 or 12 as the time duration on my noise dosimeter to calculate the time-weighted average?” Understanding how changing the time duration of a noise dosimeter sample affects the results, and how this relates to the noise standard, will help us make the best decision.
In 1995, a team of young engineers at Cirrus Research set to work on revolutionising the design and functionality of noise dosimeters. Their hard work and tireless dedication to the protection of people’s hearing led them to design the doseBadge, which has now become synonymous with personal noise exposure measurement. The process of designing the doseBadge wasn’t easy or without challenge, as the Cirrus engineers had to develop something that recorded all the necessary data, whilst ensuring that the person wearing the equipment wasn’t disturbed, and that the equipment itself complied with the Noise At Work regulations, in addition to being low cost, reliable, lightweight, tamper-proof and compliant with the acoustic standard. Some may have thought “why bother?”, but there was a recognition within the Cirrus team that dosimeters, at the time were very unreliable, cumbersome, liable to tampering and potentially dangerous, as the microphone cable could easily have been caught in heavy industrial machinery, causing serious injuries to those wearing them.
Since being posted on YouTube, Sarah Churman’s video has been viewed over 26,000,000 times. Sarah, born deaf, was 29 years old at the time, a young mother of two that had never heard her children’s voices or her husband’s snores. We see her as she hears her own voice for the first time after a cochlea implant. Her genuine expression of joy spoke to us. https://www.youtube.com/watch?v=OVasnb1vbcU.