Noise pollution in cities and hearing loss have 64% positive correlation, study reveals

For World Hearing Day, digital hearing app Mimi has published a report detailing hearing loss around the world. Using data gathered from over 200,000 participants of their hearing test, statistics from the World Health Organisation, and the SINTEF report on noise pollution, the study investigates how noise pollution in cities relates to hearing. The company hopes that the data will not only provide a unique insight into the current state of global hearing loss, but will also act as a call to action for individuals and health care providers to make better investments concerning aural health.

Dr. Manfred Gross from Charité University Hospital, Berlin, said:

While eye and sight checks are routine for most, ear and hearing exams are not. This is an issue as the earlier hearing loss is detected, the better the chances are for preventing further damage.

To conduct the report, data was gathered from the Mimi hearing test app, which allows participants to enter their age and gender, and then test their hearing. The Worldwide Hearing Index presents the average difference between a participant's true age and their hearing age in each location*.

The Average Hearing Loss Index was found to have a 64% positive correlation with Noise Pollution levels in each city, indicating hearing loss may be an outcome of living in these cities. The results of the Hearing Loss Index of each city and the Noise Pollution were mapped to range between 0 and 1. The sum of these two rankings were combined to give an overall Combined Hearing Loss Rank.

The 5 cities with the lowest Combined Hearing Loss are:

The 5 cities with the highest Combined Hearing Loss are:

Residents of *|City|*, *|Country|* were found to have an average additional hearing age of *|Average|* years, placing in position *|mimi rank|* out of the 50 cities included. This can be further broken down by sexes, with males found to have an average hearing age of *|Male|* years and females *|Female|* years. When combined with the rank of Noise Pollution, *|City|* ranked *|Overall|* out of the 50 cities included. It is this factor which ranks the tables above.

Findings of interest from the report include:

• Residents of Vienna, Austria were found to have the smallest Average Hearing Loss, meaning they suffered the least amount of hearing loss proportionate to their age.
• Residents of Delhi, India were found to have the greatest Average Hearing Loss within the study, meaning they suffered the most amount of hearing loss proportionate to their age.

The findings from the Mimi app are in agreement with current research in this area, which expects the average person to have a hearing loss of +10-20 years.

The full results of the study are represented in figure 1. Noise Pollution is plotted against Hearing Loss in order to visually demonstrate the positive correlation between the two factors.

Figure 1: This shows the relationship between the Noise Pollution (NP) and Hearing Loss (HL) indicators. Each city in the ranking is represented by a coloured circle mapped to the respective World Hearing Loss Index. This chart suggests that the higher the levels of noise pollution in a city, the higher the incidence of hearing loss. Source Mimi.

"With the Worldwide Hearing Index, we are aiming to create visibility and highlight the importance of good hearing and hearing health. Hearing is one of our most important senses, but has no lobby and little awareness so far. Smartphone technologies nowadays makes it easy to take a first step, test your hearing and get informed about one’s hearing health” adds Dr. Henrik Matthies, Managing Director of Mimi Hearing Technologies.