HCT

Loud noise kills the hair cells in your inner ear. They don't grow back, so the loss is permanent. The damage is silent and gradual, and under OSHA's dose rules every 5 dB louder doubles your noise dose, cutting the allowed exposure time in half.

Noise damage shows up first as a dip around 3,000–4,000 Hz: the noise notch. When your hearing shifts an average of 10 dB or more across 2,000–4,000 Hz from baseline (a Standard Threshold Shift), that’s an early warning, not a diagnosis. The annual test protects you, and the results are yours to review.

Foam earplugs, pre-molded earplugs, and earmuffs: what each one blocks, where each fits best, and what the Noise Reduction Rating on the package actually means once it’s derated for the real world.

A half-inserted earplug protects almost nothing. Most hearing loss from earplugs comes from poor insertion, not poor product. Roll, pull, push, hold, check: the technique that turns the rating on the box into protection on the floor.

Protection only counts while it's on and intact. When to wear it, how to clean each type, and when a flattened foam plug or cracked earmuff cushion needs replacing, at no cost to you.

The whole program gathered back into a handful of statements, so the exam tests what the training actually taught rather than what you happened to remember.

A scenario-based final assessment: missed questions come back until they are right, so nobody certifies on a partial score.