By Luis Felipe Sexto 

Originally it was just the narcotic stimulus of excessive sound. An orgy of uproar, a galloping quivering for years. All that is left are empty ears, and the punishment of seeing ties among people cut off with a single blow. A man from this world has turned deaf. Since remote times, the psychological and physical effects of a prolonged exposure to noisy sounds are known. Let`s define noise as the unwanted, distressing, upsetting and even lethal acoustic emission. The history of humanity shows that for thounsands of years the boisterous sound of drums, trumpets and other instruments has been useful in promoting and inciting to action. Romans had special legions in charge of diffusing noise to bring fear and confusion into enemy ranks during battle. In times of the two world wars, studies were conducted to discover sounds capable of provoking death. Lab animals have been exposed to intolerable sounds causing the breaking down of their nervous system. By early 19th century, civilization’s acoustic environment underwent a drastical transformation. The boundless industrial development , devoid of measures and of respect for the environment, brought progress into the society as well as many forms of contamination that are destroying today’s world. Of the latter, noise is perhaps the oldest and the most easy to generate. In the European Union, noise ranks second among all forms of aggressions to the environment. It ranks first in France and fourth in Argentina. It has both accumulative and short term effects. The “invader” not only accounts for deafness and hypoacoustic disorders; other effects , as dangerous or more, are also attributed to it: hypertension, hypotension, psychological and auditive fatigue, sleep disorders, heart conditions, stomach ulcers, body biochemical changes and so on. The growing escalade of noise in our lives is evident even in literature. For example, 43% of the sounds mentioned in the European literature have been reduced to 20% nowadays. As reported by the WHO, in 1939 adverse effects such as inefficiency at work, working time lost, and materials wasted cost the United States losses summing up to two million dollars daily. Twenty-eight years later, this figure had grown to 1460 million dollars annually. Not to mention that claims for damages and losses are not included in that figure inasmuch as in the 1970’s costs in the Los Angeles airport area alone surpassed the 4000 million dollars. The level of sound pressure may be measured by an instrument called soundmeter. The results are normally expressed in decibels (dB). In measuring auditive damage, the soundmeter is adjusted to only let through the frequencies to which human ear is most vulnerable, and the results are expressed in type A decibels (dBA). However, no matter the soundmeter’s physical reading may be, there’s a psychological and physiological noise tolerance limit for each individual. And this is valid even for animals. An eloquent discovery has been made at the English airport of Gloucestershire where the best way to frighten off birds from the landing strip is forcing these animals to listen to Tina Turner. It was demonstrated that this singer’s voice contains frequencies that actually give true headaches to the birds. From 1885 to 1989, specialists in Construction Projects and at the Hygiene and Epidemiology Institute conducted studies in several residential areas of Havana City to assess the housing fulfilment of standards regarding lighting, vibration, sound and ventilation levels. The results showed that noise was one of the two factors that affected most the population, both at home and at work. Sound levels grossly surpassed the levels established according to hygiene and norms criteria. The US Environment Protection Agency (EPA) for example, states that the safe noise level to avoid permanent auditive damage, should not exceed an average value of 70 dBA during the 24 hours, or of 75 dBA during 8 hours. In 1930, an English playwright used to spend much time trying to figure out how to create a unique atmosphere in the theatre. Robert Wood, a US physician considered a genius in experimenting, suggested him the generation of infrasound (sound signals containing frequencies below 20 Hertz). The theatre hall turned into an eerie setting where the audience experienced inexplicable live sensations of fear and uneasiness. Storms, gale winds and earthquakes are also source for this type of acoustic emissions. On the other hand, ultrasound signals (sound signals containing frequencies above 20 000 Hertz) are widely used. Ultrasound is successfully applied in medicine, in the diagnosis of industrial facilities and other science and technology entities as well.

One thing to come out clean with this topic is that sounds are both harmful and useful. The issue here is about a complex physical fact that generates its effects depending on intensity, frequency and time of exposure. Noise is a confirmed enemy of health and coexistence. Culture, education, laws…. In summary, all that might be done capable of limiting a serious situation as this would benefit personal and social welfare.

Translation by Gilda Gil
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