When we talk about sound, how loud it seems to us doesn't always match its actual intensity. We measure sound intensity in decibels (dB), which tells us the amount of sound energy in a particular space. The decibel scale is a bit tricky—it's not a straightforward relationship between loudness and sound intensity. Instead, sound intensity increases rapidly. For example, a sound at 20 dB is ten times more intense than a sound at 10 dB. A sound at 100 dB is an astonishing one billion times more powerful than a sound at 10 dB. However, two sounds with the same intensity may not seem equally loud to our ears. ALSO READ: Govt releases highly anticipated noise control guidelines Loudness, on the other hand, is about how we personally perceive sounds. A sound that seems loud in a quiet room might not stand out in a noisy environment, even if the sound intensity remains the same. To make a sound seem twice as loud, it usually needs to be increased by 10 dB. So, ten violins playing together would only be twice as loud as a single violin. ALSO READ: The unending debate on noise pollution: What is the impact on Kigali’s nightlife? It's worth noting that the risk of damaging your hearing from noise exposure depends on the sound intensity, not necessarily the loudness. If you find yourself needing to raise your voice to be heard at arm's length, the noise level in your environment likely exceeds 85 dB in sound intensity, which could potentially harm your hearing over time. Sounds below 70 dB pose no harm to hearing, while those between 70 and 85 dB might be perceived as annoying. However, exposure to sounds ranging from 85 to 150 dB can lead to hearing damage, loss, pain, and even ear injuries. To give you an idea of everyday sounds here are some examples: · Softest sound: 0 dB · Normal breathing: 10 dB · Ticking watch: 20 dB · Soft whisper: 30 dB · Refrigerator hum: 40 dB · Normal conversation and air conditioner: 60 dB · Washing machine and dishwasher: 70 dB · City traffic (inside the car): 80-85 dB · Loud entertainment venues (nightclubs, bars, rock concerts): 105-120 dB · Firecrackers and gunshots: 140-150 dB How are decibels measured? When it comes to measuring sound, sound level meters (SLMs) are used to quantify decibel levels for community noise analysis, building acoustics, industrial noise control, and more applications. There are even free SLM smartphone apps available for Android and iOS devices, allowing individuals to gauge the sound intensity in their surroundings. The World Health Organization (WHO) recommends maintaining environmental noises below 70 dBA over 24-hours (75 dBA over 8-hours) to prevent noise-induced hearing loss. Disclaimer: The information in this article was derived from public sources provided by the Centers for Disease Control and Prevention (CDC).
