The natural phenomenon measured in decibels is sound intensity or loudness. Decibels (dB) provide a logarithmic scale of measuring the pressure or intensity of sound waves. This measurement helps quantify the amplitude of sound, allowing for comparisons between different sounds. For instance, a whisper is around 30 dB, normal conversation is approximately 60 dB, while sounds like a jet engine can exceed 120 dB, which can be harmful to hearing. Understanding sound intensity in decibels is crucial in fields ranging from acoustics to engineering and health.