How loud is a decibel?

The loudness of a decibel cannot be defined in absolute terms due to the logarithmic nature of the decibel scale, which measures sound intensity relative to a reference sound. However, the scale starts at the faintest sound the human ear can hear, defined as 0 dB, and progresses to sounds of increasing intensity. For perspective, a quiet whisper is around 30 dB, normal conversation falls around 60 dB, busy traffic might be around 85 dB, and a rock concert can reach levels of 120 dB or more. The perceived loudness of a sound doubles with every 10 dB increase, making a sound at 70 dB seem twice as loud as a 60 dB sound. This relative measure helps in understanding the wide range of sounds the human ear can perceive, from the barely audible to those that can cause immediate hearing damage.