Understanding Sound Decibels: A Guide to Measuring Loudness

When we hear that something measures '85 dB', do we really know what that means? Unless you're a hearing professional, it's not particularly helpful information. To truly understand just how loud something is, we need to grasp the concept of decibel charts and the way sound levels are measured.

To put it simply, if a sound is 20 dB, it's 100 times louder than near silence. And near silence itself is expressed as 0 dB – but a sound measured at 10 dB is actually 10 times louder. Every increase of 10 dB on the decibel scale represents a 10-fold increase in sound pressure level (SPL), which is exponential, not linear.

But what does this mean in everyday life? We often think of volume when discussing loudness, and that's correct – but it's more complex than just turning up or down. Decibels are measured logarithmically, meaning the more amplitude a sound has, the louder it is. This is why sounds that are 10 dB louder may not seem like much at first, but a 20 dB increase can make a significant difference.

So what do we measure when talking about sound intensity? It's all about amplitude – or the forcefulness of the sound. Decibels measure sound intensity, which is reported on the decibel (dB) scale. This means that sounds with higher amplitudes are louder, and those with lower amplitudes are softer.

But what about frequency? This measures the number of sound vibrations in one second, reported in Hertz (Hz). There are two ways to measure frequency: amplitude and frequency itself. Decibels focus on sound intensity (amplitude), while frequency looks at the actual pitch or tone of the sound.

In everyday life, we experience this difference when dealing with high-frequency hearing loss, which affects many older adults. This makes it harder to hear sounds that are higher pitched, like a child's voice. On the other hand, low-pitched sounds are generally easier to detect.

From the soft whisper of a grandchild sharing a secret to the loud blare of a fire truck's siren and the soothing melody of your favorite song on the radio, sound is all around us. By understanding decibels and how they measure sound intensity, we can better appreciate the world around us – and maybe even take steps to protect our hearing in the process.

Sound decibel scale