If you are a 30-year-old who lives in Mumbai, you have the hearing ability of a 49-year-old.
The World Hearing Index – a global ranking developed by researchers at Mimi and Charite University Hospital in Berlin – found that the average hearing loss for Mumbai citizens is +18.58 years. This means that a person in Mumbai has the hearing ability of someone almost 19 years older.
While Delhi ranked first for average hearing loss at 1, Mumbai was a close second, at 0.98.
This makes Mumbai the second-worst in the world for average hearing loss – or reduced hearing ability – of the 50 cities that were studied. New Delhi was ranked first.
The international study, released on Friday, further broke down the statistics for men and women. While women were found to have an average hearing loss of +18.77 years, men were found to have the hearing ability of an individual 18.40 years older.
The Berlin-based university hospital carried out the study by collecting data from more than 2 lakh hearing tests worldwide and combining this with information from the World Health Organisation (WHO) and Norwegian-based technology research group, SINTEF, to create a noise pollution index. “The hearing age is calculated using a hearing test in the form of an app. The difference between the actual age and hearing age of a participant is presented as a figure, representative of hearing age years additional to the participant’s actual age,” read the study.
Meanwhile, each city was ranked on a scale from 0 to 1. While 0 was assigned to the city with the lowest average hearing loss, 1 was for the city with the highest. The noise pollution levels from each city were ranked in the same way. These two statistics were combined to create the Combined Hearing Loss Index.
The lowest average hearing loss rank was Vienna, Austria at 0, followed by Hamburg, Germany at 0.1. Mumbai was fourth worldwide under the Combined Hearing Loss Index at 1.67 after Guangzhou, China (1.82), New Delhi (1.72) and Cairo, Egypt (1.7). However, for the noise pollution rank, Mumbai was ninth in the world.
“The average hearing loss result was found to have a 64% positive correlation with noise pollution levels in each city, indicating hearing loss may be a direct or indirect outcome of living in these cities,” the study said.
“We hope the study will not only raise awareness among residents of cities and governing institutions, but will act as a call to action for individuals and health care providers to make better investments concerning aural health,” it added.
City doctors said the study came as a revelation and was a grave concern for Mumbai. “The study shows that a 25-year-old actually has the hearing of a 44-year-old. Youngsters today are exposed to noise from loud music, industrial noise, aircraft, all of which affect their hearing. Once the damage has occurred, there is no treatment,” said Dr Ashwini Mehta, ENT specialist, Seven Hills Hospital, Andheri. “With age, hearing goes down, but this study shows hearing disabilities are now starting at a much younger age.
“Even 17 years after the noise rules were passed and countless Supreme Court and High Court orders, we are still struggling with allowing our citizens to have major issues related to deafness. There are a host of other issues related to hearing loss such as mental health problems, heart disease and chemical imbalances. As a city, we know this information but we are refusing to draw that link and our politicians are still making excuses to allow noise saying that noise limits are not practical for Indian megacities,” said Sumaira Abdulali, convener, Awaaz Foundation.