Which of the following is a sign that hearing protection might be necessary?

A sign that hearing protection might be necessary is when workplace conversations become difficult to hear. This indicates that the ambient noise level may be high enough to pose a risk to hearing. Noise levels at this threshold can lead to auditory fatigue or potentially damage hearing over time. When conversations, which typically occur at around 60 decibels, become hard to discern, it usually suggests that the surrounding noise is at a level that could necessitate the use of hearing protection to safeguard auditory health. Being proactive in recognizing this sign helps ensure a safer work environment, particularly in settings with machinery or multiple sources of sound.

The other choices either reflect situations where hearing protection may not be necessary or do not adequately indicate high noise levels that require such measures.