Hearing loss is a serious issue for both adults and children, with the NHS claiming that in 2015, 1 in 6 people in the UK had experienced hearing deficiency (NHS England and Department of Health, 2015). This report will cover the reasons behind this ongoing problem, and identify why so many of people have far from optimal hearing.
Physiology of the ear
The human ear consists of 3 parts; the outer ear, middle ear, and inner ear, all of which work together to convert sound pressure waves into electrical nerve impulses that the brain can understand. The parts of the ear directly related to hearing loss include the ear drum, and the cochlea, which are components of the middle and inner ear respectively.
The two types of hearing loss, sensorineural and conductive, differ based on what area of the ear has been damaged and how this damage affects the rest of the hearing process. Sensorineural hearing loss is permanent and is a result of impairment of the auditory nerve and/or the hair cells within the inner ear. These hair cells are found in the cochlea, a tiny spiral shaped bone filled with fluid located in the inner ear, and are responsible for distinguishing between different frequencies and then sending this information to the brain through the auditory nerve. According to (Solomon, 2015) PhD; “Sounds of a given frequency set up waves in the cochlear fluid” and then “the brain infers the pitch of a sound from the particular hair cells that are stimulated”. Exposure to loud noise can break the connections between the hair cells and the auditory nerve which then, in absence of its regular input, causes the fibres inside the nerve to transmit infinite messages to the brain. It is these constant messages that result in the ringing noise associated with tinnitus, which affects “approximately 10% of the UK population” (Ludman and Bradley, 2012). Sensorineural hearing loss can also be caused by age, skull damage, and ear infection.
Conductive hearing loss takes place in the outer and/or middle ear, and can be caused by a blockage or malformation within the ear that prevents the cochlea from conducting sound. This damage can be the result of changes in air pressure due to impact, altitude, loud noise, as well as serious ear infection. The breakage to the ear drum can be temporary or permanent, and hearing will restore if and when it heals. According to leading hearing solutions company MED-EL, these types of hearing losses “are usually mild or moderate in degree, ranging from 25 to 65 decibels” (Medel.org, n.d).
Levels, devices and places
Levels
Any sound louder than or equal to 85dB has the potential to damage human hearing, but this all depends on the length of exposure. The National Institute for Occupational Safety and Health in the United States estimate that, in order to preserve hearing, the human ear can only be exposed to 85dB of noise for 8 hours, and from then on, the length of exposure must be halved at intervals of 3dB (Cdc.gov, 2016). Exposing the human ear to sounds at these levels for an inappropriate length can cause the hair cells inside the cochlea to die, which is directly linked to sensorineural hearing loss and tinnitus. Exponentially louder sounds can directly damage the ear drum, and according to American healthcare practice Better Hearing of Austin; “the noise intensity to rupture an eardrum would have to be very loud, usually 165 decibels or more” (Betterhearingofaustin.com, n.d).
Devices
When on maximum volume, devices such as smartphones and portable media players can emit sound through headphones at levels between 95dB and 105dB (Dillner, 2014). If the ear is exposed for too long, this output level is high enough to cause noise induced hearing loss, which is dangerous seeing 2016 saw 1.86 billion people using smartphones (Statista, n.d). Loudspeakers also have the potential to damage hearing, especially the rigs found in live music venues and clubs. Companies such as Void Acoustics, RC1, and Funktion-One all manufacture professional audio systems, before distributing them throughout the live sound market. When not used in a controlled environment these sound systems can be turned up to dangerous levels, which in turn can create an unsafe environment for the audience.
Places
The workplace, live music venues and clubs can all produce hazardous levels of noise. Workplaces such as airports and construction sites surround employees with various loud vehicles and machines, and hearing damage can occur if the correct protection isn’t available. Soundproofing experts Acoustical Surfaces claim that “workers who direct jet engines in landing and take-off are subjected to 140 dB of sound in one go” (Hse.gov.uk, n.d), which is 20dB above the threshold of pain and 55dB above the threshold of potential hearing damage. Regular exposure to these levels of sounds can and will result in hearing loss, which is why employers must ensure that they take correct safety precautions.
When receiving frequent bookings at nightclubs, DJ’s can also be at risk of hearing loss. In 2016, music journalist (Jenkins, 2016) published a report on leading electronic music news network UKF, where he interviewed leading drum and bass DJ’s on their experiences with tinnitus. When interviewed, Andy C (successful DJ and co-founder of Ram Records) says “I still remember the very night I made the decision to invest in good hearing protection. It was my third show of the night and the monitors were screaming. As I was driving back from the show I was in pain in my ears” He then goes on to explain how scary it was, before saying “literally the next day I was booked in with an audiologist and got my moulds done.” This is a first-hand account of a leading DJ’s experience with ear damage, which proves the potential risk involved when working in nightclubs and music venues.
Law and regulations
As a result of the noise levels discussed in the previous section, governments around the world have implemented laws and regulations to help minimise cases of noise induced hearing loss throughout employees and the general public. In the UK, the first legislation regarding high sound levels in the workplace was the Noise at Work Regulations 1989, but this was then revised into the Control of Noise at Work Regulations 2005. These new regulations were enforced upon all workplace environments from the 6th of April 2006, and then on the entertainment sector exactly 2 years after. According to the UK Health and Safety Executive, the purpose of the Noise Regulations is to “ensure that workers' hearing is protected from excessive noise” as this could “cause them to lose their hearing and/or to suffer from tinnitus” (Hse.guv.uk, n.d). Under these regulations, employers must supply suitable hearing protection if their employees are exposed to sound levels between 85dB and 87dB, and after taking account of the reduction of exposure caused by this protection, levels above 87dB are not permitted. (Ludman and Bradley, 2012) from the National Hospital for Neurology and Neurosurgery and Nottingham University Hospitals respectively, claim that employees “most susceptible” to hearing damage “are those using firearms or power tools such as jackhammers without adequate ear defenders, and those who are regularly exposed to excessively loud music”. Therefore, it is crucial that employers obey these laws to ensure the safety of their workers.
Conclusion
In conclusion, the reasons behind why so many people have been affected by hearing loss have been made clear, and whether or not hearing loss is an ongoing problem in the future is dependent on how we choose to behave. Up until the introduction of legislation such as the Noise at Work regulations 1989, people’s loss of hearing was not always their own fault, as they may have been unknowingly exposed to dangerous noise levels. When thinking forward it is reasonable to assume that at this point in time, sufficient research has been done to minimise cases of noise induced hearing loss in the next generation, as long as the public become aware of the risks and are proactive in protecting their ears. Personally, I am aware that my lifestyle choices have had a negative impact on my hearing, because I have never made safety my top priority. For this reason, from this point onwards I will take appropriate action to protect my ears, starting by wearing earplugs when attending nightclubs and concerts, and avoiding prolonged exposure to dangerous noise levels.