Which sound level would likely not cause permanent damage?

When evaluating sound levels and their potential for causing permanent damage to hearing, it's important to understand the relationship between decibel levels and the risk of hearing loss. At 80 decibels, the sound is typically considered to be at a level that can be tolerated for prolonged periods without the high risk of permanent hearing damage. This level is often associated with sounds like heavy traffic or a vacuum cleaner, which many people encounter without significant adverse effects on their hearing.

In contrast, levels above 80 decibels, such as 100 decibels (which can come from chainsaws or rock concerts), significantly increase the risk of hearing impairment, especially with extended exposure. Sound levels of 130 decibels (like a jet takeoff or gunshots) and 150 decibels (approaching noise levels of a rocket launch) are extremely dangerous and can cause immediate hearing damage or permanent loss after even very brief exposure.

Therefore, the sound level of 80 decibels is the only one in the choices presented that is generally accepted as being safe for longer durations without an immediate risk of causing permanent damage to hearing.