Making SENS of noise induced hearing loss

It is estimated that 130 million people in the developed world now have some degree of hearing loss. In the workplace, according to research conducted by the World Health Organisation, noise induced hearing loss (NIHL) is one of the most common occupational illnesses. 

The situation where people struggle the most is when they are in a high noise situation, that is, in an environment with extremely high background noise (eg a plant) that prevents them from being able to communicate with each other effectively above the noise, even when raising their voices in an attempt to be heard.

NIHL is now considered to be a major occupational health and safety issue in Australia. According to Access Economics in its 2006 report ?The Economic Impact and Cost of Hearing Loss in Australia?, one in six people now suffer from hearing loss and this is expected to grow to one in four by 2050. 

It is estimated that 158,876 people were not employed in 2005 for reasons of impaired or lost hearing.

While hearing aid companies have developed innovative products with more sophisticated technologies and greater miniaturisation to better cater for hearing loss sufferers, hearing protection companies have been relatively slow in the development of innovative new product releases that address the key human drivers relating to noise exposure in the workplace.

It is also clear that despite the best efforts of employers to abide by the compliance standards of WorkSafe Australia and Australian Hearing to provide a safer, less noisy work environment, the incidence of hearing damage is still widespread. Australian Hearing recommends that personal protective equipment such as earmuffs and earplugs should be worn when workers are exposed to noise levels at and above 85 decibels (dBA) for over eight hours at a time. 

However, studies have shown that noise exposed workers still do not consistently use their hearing protection because their protectors inhibit them from communicating in high noise environments, interfere with job performance and productivity (by making certain sounds from machinery undetectable) and impede their situational safety. Human factors, therefore, are the key to the implementation of a successful hearing conservation programme. The challenge to minimising NIHL is to ensure the above human drivers for non-compliance are addressed by the hearing protection devices allocated to the workers.

In October 2008, as part of National Work Safety Week, Australian technology company Sensear introduced its Speech Enhancing Noise Suppression (SENS) earmuff. The technology, which originally evolved out of a joint venture between Curtin University and the University of Western Australia and has since been commercialised by Sensear, is designed to minimise dangerous industrial noise while allowing face to face, mobile phone and two-way radio communication. SENS is considered to be the first of its kind in the world and as a result, Sensear has applied for a patent.

?The electronic hearing protection systems that preceded Sensear do contain microphones but they are designed to mask very sharp, high impact noises such as gunshots and only allow communication when it?s quiet,? Justin Miller, the chief executive officer of Sensear, explained in an interview for Quarry. ?The same for active noise cancellation headsets such as you use on aircraft travel.  They cancel out all background noise including speech.  Herein lies the problem as both these technologies are designed to cancel noise; neither has been designed to allow safe speech.

?The number one reason that people remove their hearing protection is to communicate; the second is in order to hear machinery, which is critical. With the SENS, we offer both – the ability to communicate and to allow the wearer to retain their situational awareness, so you?ll hear, for instance, the wheel loader coming from a particular direction. With the SENS, we don?t eliminate the noise, we just lower it to a safe level so you can still hear sound and retain your directionality of all of the sounds in your environment, and then we promote speech over the top of it.  The message we had from our customers was that you?re not going to sell hearing protection and noise suppression systems unless you keep the hearing protection on their workers? heads – and the best way you?re going to do that is to enable them to talk face to face, talk on their two way radios, talk on their mobile phones, and also allow them to retain their situational awareness.  If you can solve those things, then workers will wear them. 

With the SENS, I believe we have solved those problems. We received feedback from our marketers about what our customers wanted and our prototypes were then put back through their paces at all of our customers? work sites continually until we developed the product that they actually wanted to buy.?

To that end, Sensear has released the 440 gram SM1 and SM1x earmuffs which employ the SENS technology, offer full stereo sound quality at a safe 82dBA in the ear in noisy environments above 85dBA and over 12 hours of continuous talk time before recharging. The SM1 (in yellow high visibility colours) and SM1x (in orange) feature auxiliary input with protector cover, a two way radio interface connector, a dual microphone pick-up for clear communication, MP3 interface and a battery charge LED indicator. The SM1x also comes with Bluetooth mobile phone connectivity. Both the SM1 and the SM1x also have the option of a helmet mount, also in matching yellow and orange high visibility colours.

Sensear also still offers the original and lightweight SP1 and SP1x earplug system, the precursor to the SM1 and SM1x earmuffs, again with full stereo sound quality at 82dBA.The 120 gram units also offer auxiliary input with protector cover, a multi-directional microphone for clear communication, a battery charge LED indicator, high visibility safety colours (yellow for the SP1, orange for the SP1x), easy to use volume control buttons, a flexible strain-relief cable and replaceable multi-fit soft earplugs. The SP1x also features Bluetooth mobile phone connectivity.

Before its product became available on the market, Sensear conducted extensive field tests of the SENS technology with prospective customers in the mining, construction, aviation, manufacturing, transport and hospitality industries. ?What we set about doing was developing something wearable that we could take out to the big mine sites for field testing,? Justin Miller explained.  ?For me, the initial reaction of our customers was enough to show me that there was a real noise problem here that needed to be solved.?

Part of Sensear?s business plan from the outset was to obtain input from the mining industry. ?My first experience with field testing the SENS was on an Alcoa rod mill,? Justin recalled. ?We field tested the earplugs on a couple of operators who had already lost their hearing.  These workers had been working for over 20 years and the positive reaction that we had from those guys was enormous.  You do get the ?wow factor? when you put the Sensear devices on and these guys for the first time in their working environment could communicate with each other.  

?We have another customer who was quite unique in terms of the mining game. They use conveyor belts to transport their ore and require some of their workers to listen out for malfunctioning or squeaky rollers. As the overall noise is above the threshold, inevitably these guys go deaf over time. What our product enabled them to do was detect the noise of the roller a lot better, because we had brought the sound down to a safe level. They could then actually find the roller that was squeaking a lot easier.

?The significant learning that we took away from these field tests was that that the Alcoas and the Rio Tintos of the world wanted this noise problem solved because their incidents of NIHL continued to increase.?

The input of the big miners into the design and development of the Sensear earmuffs and earplugs would eventually be quite influential,
particularly in relation to battery life. ?We had to get the battery life to a point where it could cope with an extended shift, a minimum of 14 hours before recharge, because we use rechargeable batteries,? said Justin. ?That, along with the capacity for two-way communication, was very important in the robustness of our case to industry.

?Irrespective of the industry, noise surrounds us and everyone has the same issue with their inability to communicate in high noise environments.  We took some of our units into nightclubs to enable bar staff to communicate, to enable security to communicate, so it doesn?t matter what that noise is, people struggle in all sorts of environments to communicate.  We are just finding more and more unique areas that the products have applications in and broadly speaking, anywhere that has high noise and the need to communicate, we have a solution. About 80 per cent of one of our large mining clients? workforce is noise exposed, and almost all of those have a need to communicate, so that?s many thousands of people who have a problem within the one company.?

Although many suppliers to the quarrying and mining industries themselves have spent considerable amounts of time, research and money on noise suppression within plant and machinery and within the cabins of heavy mobile vehicles (eg loaders, dump trucks, graders, rigs, etc), Justin Miller did not believe that this would be a disincentive to quarrying or mining operators to invest in the SM1 or SM1x headsets for their workers.

?As a layman who has spent a lot of time in large dump trucks and the like on mine sites, I have to say it?s almost a chaotic experience,? he said. ?You have the noise of the truck combined with the two way radio, the driver has to turn the noise of the radio up above the noise of the truck and they also have to listen out for sounds from other drivers on the site because the way they communicate is through a number of honks, in terms of ?this one?s going to trash, this one?s going to refinement, this one?s going straight to the train?, so there are all sorts of sounds competing for attention. All of that sound actually removes the drivers from their ability to do their job productively.  It?s not quiet in the cabin, for whatever reasons.  And the ability then for the driver to leave the cab and still be in communicado is pretty significant as well.?

Justin argued that a driver would benefit from wearing a headset in the cabin of a heavy vehicle, as it would improve their situational awareness. ?It actually enhances their concentration in my experience.  If we can encourage drivers to wear the headsets, then we bring the background noise level down. They can hear their machinery a lot better, they can hear what?s going on around them a lot better, and we won?t have compromised their ability to communicate. The volume can?t be raised above 82dBA, so that is quite comfortable on the ear. It?s the noise that is the distracting thing.?

While he does not pretend that the SENS technology will provide a long term solution to the problem of NIHL (this will require further long term study and qualified product status) or necessarily increase productivity amongst workers, Justin Miller stated that as a communication tool, it has so far been very popular amongst Sensear?s customers and their workers.

?It?s a little early to say that we?re solving noise induced hearing problems,? he said. ?We?re certainly enabling far more effective communication and that is because people can hear, and there is a discernible difference in wearing our systems and not wearing our systems. In many respects, the safety aspect of it is secondary in favour of the ability to communicate; this ability is the clear winner. Nevertheless, the fact that if you leave it on you can?t turn it up to anything above 82dBA means that we?re potentially keeping the individual safe as well.

?It is hard to measure whether there?s been any productivity gains amongst our customers but the fact that people are communicating better suggests this could contribute to productivity. We?ve worked with Kylie Hooker, who is the occupational hygienist for the St Ives Gold Mine in Kambalda in WA and she highlighted a case where someone who was hard of hearing wore our headset and in the working environment it improved his ability to communicate.?

The challenge, he added, was to persuade workers to wear the earmuffs. ?The drivers for acceptance of a product are very different from a company?s perspective and from an individual?s point of view.  The company loves the product because it potentially solves their governance and safety concerns.  The individual unfortunately isn?t necessarily aware of how important hearing protection is – if our ears were to bleed if exposed to high noise, it might be different, but they don?t – it?s not like a cut that you can treat on the same day, hearing loss is incurred in the long term.

?An individual will wear the Sensear hearing protection not necessarily to protect themselves or make themselves safe – for them, the driver is the ability to communicate in a high noise environment, so without the Sensear devices, they can?t talk, and with them they can.  So workers can talk about what they did last night or on the weekend and have a normal communication relationship with their workmates as people in most noiseless industries do. That?s what we see the individual actually accept – because without it they can?t talk, with it they can. It?s not necessarily the safety aspect that?s making them wear it.?

Justin stated that the level of ambivalence amongst workers was not necessarily confined to any one demographic in the workforce. Baby boomers, Gen Xers and Gen Yers alike are just as likely to forsake their hearing in order to hear instructions correctly and to communicate effectively with their peers.

He added that this would require further education and Sensear has applied to the Federal Government for a grant so that it can develop an education programme for its market that will go hand in hand with demonstrations of the SENS technology. ?Education in the workplace isn?t working – people still avoid protection.  So if we can get our product out there, and get people using it in many different environments, then that may solve the problem.?

While most of Sensear?s work with the SM1 and SM1x earmuffs has been with the mining industry, Justin Miller believes the technology can make a seamless transition into a quarry application.

?Our message is the same in any high noise environment and I would imagine that in quarrying, as in mining, if you have a need to communicate more effectively in order to do your job then we have a solution to that problem.  That?s not just a problem in communication but also a safety problem in long term noise exposure.  For us, our message is simple – clear, safe communication in high noise environments whilst also maintaining situational awareness. We can enable that and perhaps indirectly enhance the prospects of productivity gain through people staying safe, staying in the workplace, and being able to communicate. Being anywhere and being able to communicate is pretty significant.?

For further information about Sensear and its advanced SENS technology, visit

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