Noise pollution

By Nicole Namubiru

Are you exposed to these danger signs?

As I write this article, there is a sharp metal-on-metal grinding noise outside my office window. I suspect it is an electric metal grinder. It could be an electric saw cutting timber. I can also hear someone nailing something.  Farther away, in front of the office block, there is another continuous noise. It is a nagging noise like someone outside is banging the wall with something soft. All this noise makes me feel a relentless rolling reel of pain inside my head.

Luckily for me, I am not having to talk to someone. But I can see that my office colleagues, who are talking to each other, are having to raise their voices. I am barely two desks away from them but I cannot hear what they are saying.

What I have just described are possible noise sources around any office in Kampala or other major urban centre in Uganda. Construction sites are major sources of constant noise. But urban traffic; roaring lorries, buses, mini-buses, and cars, and motor vehicles are the biggest noise polluters.

Unfortunately, few Ugandans know the danger of constant exposure to traffic noise; which is about 85 decibels or measures of the intensity of sounds. The lowest decibel is zero and the highest is over 165 decibels. A whisper in the ear is about 20 decibels, and the sound of gunfire is about 165 decibels. Normal conversation is about 60 decibels.

People in night clubs, social events, taxi parks, and some places of worship, may be exposed to sounds of decibels as high as 100 decibels. But very few of them know that continuous exposure to this level of noise for more than 30 minutes could impair their hearing.

How loud is loud?

Dr. Abubaker Bugembe, an Ear Nose and Throat (ENT) specialist, says everyone is prone to noise-borne hearing impairment if caution is not observed when doing regular activities like being near a crowded street or listening to music at home through our home theatre or with headsets. He says normal sound should be like the tone one uses in a normal conversation which is between 45 to 60 decibels. Anything above that is loud sound.

In case of an extreme and abrupt sound; like a bomb blast, one can lose their hearing ability. This is because such sounds, although lasting only seconds or at most a few minutes, have very high decibels of 90 and above.

“In circumstances when one is frequently exposed to loud sound, chances of suffering hearing loss are high,” Dr. Bugembe says, “Similarly, a person that is exposed to highly intensified sound stands the same risk.”

This may be a permanent or temporal damage depending on the intensity of the sound one is exposed to or the frequency of how much one gets exposed to this sound.

Take Masoudi Ngobe Sentongo aka Doctor Suudi. As the sound technician and advert producer at a radio station, he has no option but to listen to sounds via headsets for most part of his working day.  After doing this for the last ten years, the effects are starting to be noticed.

“I barely hear people when they talk to me in a normal voice tone,” he says, “I often ask them to raise their voices so I can hear them well.  This has been the case for four years now.”

Bugembe says a problem like Suudi’s starts with the victim hearing an internal hissing sound in their ears. He says this usually occurs after someone walks away from the loud sound.

“The unfortunate thing is that hearing loss is a permanent problem. It is irreversible since the damage is done on the nerve cells,” says Dr. Bugembe, “The best that we usually recommend for such people are hearing aids.”

The good news is that when one notices early signs of hearing loss; like pain in the ears or a hissing sound without necessarily having their hearing reduce, the condition can be reversed by avoiding exposure to sound above 90 decibels.

It is also true that even when one continuously wears headsets but controls the sound reasonably, they may not suffer hearing loss.

William Kasirye, another sound technician who has worked for 30 years, is free from hearing loss.

“I control the sound to reasonable levels, I never let it blast in my ears,” Kasirye explains, “I always detect and know what sound is good and what is bad.”

The precautions work for him; he hears clearly enough.

People that have hearing loss usually talk with their voices raised. They think they are not being heard and it is the same high pitch they expect their correspondent to respond back to them. This is why experts advise that it is important to avoid being exposed to loud sound. Although it may not impair one’s hearing to the point of deafness, it can lead to levels of failing to conduct a low tone conversation.