Methodology
According to (www.london.gov.uk, 2022) The major sources of noise pollution in London are roads, rail and aviation. Environmental noise has been recognised by the World Health Organisation (WHO) as the second largest environmental health risk in Western Europe, behind air quality.
Prolonged exposure to excessive noise has been shown to have harmful effects on mental and physical health, including impaired cognitive development in children, tinnitus, sleep disturbance, and even heart disease.
After researching information around sound pollution, such as that noted above, we decided to conduct our own research into the noise in our daily lives and how it may be impacting us in ways that we never realised. We wanted to accumulate data around the noise we each experience everyday in a form that we could all relate to. For this reason, we decided to record the sound levels of each of our individual journeys from our homes into uni (Greencoat) and to compare our results. This theme also coincided with the data above, in that the main noise pollutants are methods of transportation (roads, rail and aviation), which we all interact with in our daily commutes onto campus.
By recording our individual journeys from our homes, all in varying parts of London, into uni, we aimed to uncover and highlight any disadvantages that some of us may be at, simply by living in a certain area or by having to take a specific form of transport to reach our destination. In this way, we wanted to highlight how seemingly trivial details of a person's life, such as where they live, how they travel and where they work, can actually have consequences much larger than anyone acknowledges due to the many infrastructures that run through our daily lives.
After conducting some research into the best way to collect and record our sound data, we found an app called ‘NIOSH SLM’ (National Institute for Occupational Safety and Health, Sound Level Meter). The app is developed by experienced acoustics engineers and hearing loss experts, featuring sound level metres and noise dosimeters to allow people to record and monitor the sound levels in their environment. It is fully tested and validated according to standards in a reverberant chamber at NIOSH acoustics lab.
Over the course of the recording, the app monitors the total run time of the recording, the LAeq, Lmax, LCpeak, TWA, Dose and Projected dose, all of which I have defined below:
LAeq - Equivalent Continuous Sound Pressure Level, or Leq/LAeq, is the constant noise level that would result in the same total sound energy being produced over a given period. LAeq is a fundamental measurement parameter designed to represent a varying sound source over a given time as a single number.
Max.level - The Max level is the maximum RMS sound level with a time constant applied (Fast or Slow) and is very different to the Peak. In the Noise at Work Regulations 1989, action must be taken when the Peak level gets to 140 dB(C).
LCpeak - LCpeak - The Peak Sound pressure level with 'C' frequency weighting. LCS. The Sound level with 'C' Frequency weighting and Slow Time weighting.
TWA - Time Weighted Average Noise Levels - The TWA shows a worker's daily exposure to occupational noise (normalised to an 8 hour day), taking into account the average levels of noise and the time spent in each area.
dB - Decibel - The decibel is a relative unit of measurement equal to one tenth of a bel. It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a power ratio of 101/10 or root-power ratio of 10¹⁄²⁰.
Once discovering the app and researching its accuracy and validity, we decided that it was the most efficient and accessible recording device for us to use for our data collection.
Using the app, we each began recording our journey the minute that we left our homes and didn’t stop it until we reached Greencoat. We held our phones out in front of us for the entire duration of the trip (no leaving it in our bags, covering the microphone with our hands, or using other apps simultaneously) to ensure that the recordings weren’t unfairly interfered with. We all used our iPhones for the recording, meaning the microphones were consistently the same (omnidirectional (omni) condenser mics).
We also decided to produce field recordings at specific coordinates throughout our individual routes, alongside the recorded sound data we collected. The idea behind the recordings was to provide more context to the data we collected and give real examples of the noise levels in those specific locations. They would act as both an information source for people living in similar areas of London and as evidence for the data we each collected.
We took inspiration from Lawrence Abu Hamdan, a contemporary artist, based in Beirut, whose work looks into the political effects of listening, using various kinds of audio to explore its effects on human rights and law. He is a prime example of how audio and sound can be used on a political and social level to spark positive reform on a governmental level. For example, some of his audio investigations lead to him testifying as an expert witness in asylum hearings in the UK.
(Smiley, 2015) notes that “The field observation, an ethnographic practice of collecting data and information about a given social setting and situation is often used in preliminary research to have an understanding of the community one is researching.” He highlights the similarities between field observation and audio field recordings, and how they could be used simultaneously to record more conclusive and informative data about a given social setting or community.
In this way, we wanted to use our field recordings as a means of analysing and deconstructing the infrastructures that surround our daily lives, all the way down to mundane activities such as commuting to work or university. There are so many hidden and unspoken dangers and biases across different demographics and areas of London that could make an individual in one area much more likely to obtain negative side effects from sound pollution, than another living in an alternative area. Our field recordings aim to raise awareness for and start a conversation of this kind.
Our final step in making our collected data accessible and comprehensible, was to make an interactive map. Our map marks five specific coordinates on each of our journeys into uni, with a small circle. When the viewer clicks on each circle, the field recording from that location is played. This was the final step in displaying the data we collected and sharing it in a way that was both engaging for the viewer but also informative and thought provoking.