Thunder, a powerful natural phenomenon, is the booming sound that follows a flash of lightning during a thunderstorm. Many people wonder about its loudness, especially when it occurs nearby, and its potential effects on hearing.
The Science Behind Thunder’s Roar
Thunder begins with a lightning flash, an electrical discharge heating the air along its path to extreme temperatures, up to 54,000°F (30,000°C). This rapid heating causes the air to expand explosively, creating a shockwave that travels outward from the lightning channel.
This shockwave is what we perceive as thunder. The sound’s character, whether a sharp crack or a prolonged rumble, depends on the lightning’s path and your distance. We always see lightning before hearing thunder because light travels faster than sound.
Measuring Thunder’s Intensity
Sound intensity is measured in decibels (dB), and thunder’s loudness varies significantly based on proximity to the lightning strike. When thunder occurs very close, it can reach levels between 100 and 120 dB, comparable to a jet engine at takeoff or a loud rock concert. For extremely close strikes, such as “superbolts,” the sound can reach up to 160 dB.
Prolonged exposure to sounds at or above 85 dB can cause hearing damage over time. Sounds exceeding 120 to 140 dB can cause immediate pain and pose a risk of immediate hearing damage. While thunder is loud, its transient nature—a brief burst rather than continuous exposure—plays a role in its overall impact on hearing.
Protecting Your Hearing From Close Thunder
While thunder is powerful, direct hearing damage from it is less common than injuries from lightning strikes. However, being very close to a lightning strike can produce a shockwave intense enough to cause temporary hearing impairment or, in rare instances, permanent damage. Such events are typically associated with a direct strike or very near-miss.
The primary safety measure during a thunderstorm is to seek sturdy, enclosed shelter, such as a building with plumbing or electrical wiring, or a fully enclosed vehicle. This protects against lightning, which is the greater danger. If thunder is heard, it indicates lightning is close enough to be a threat. Focusing on overall lightning safety provides the most effective protection during a storm.