Roll it down thin, pull the ear up and back to straighten the canal, insert, and hold until it expands.

Rolling has to reduce the plug to a thin crease-free cylinder - a partially rolled plug cannot go deep enough.

Reaching over the head to pull the opposite ear straightens the canal, which is what allows correct depth.

Holding the plug in place while it expands is the step most often skipped, and it takes a few seconds.

A correctly fitted plug leaves only a small part visible from the front.

Clean hands matter, because whatever is on them goes into the ear canal.

Because the rating is a laboratory figure achieved under ideal fitting, and real insertion varies enormously.

A plug that is visibly in the ear but not deep enough still makes things quieter, so the wearer has no feedback.

Studies consistently find average field attenuation well below rated values for foam plugs.

Variation between wearers, and between insertions by the same wearer, is large.

Training and fit checking close most of the gap at almost no cost.

Fit testing systems that measure actual attenuation on the individual are increasingly used where the risk justifies it.

They are single-use, and reuse is a genuine infection route rather than a fastidious objection.

Foam is porous and picks up whatever is on the hands that rolled it.

A plug that has been in a pocket carries that into the ear canal.

Used foam also loses its recovery characteristics and no longer expands properly.

Dispensers at the point of use are what make single-use practical, because plugs are then always available.

Reusable flanged plugs are the correct product where repeated use is wanted.

No - over-protection isolates the wearer from speech, warnings and vehicle noise, which is its own hazard.

In moderate noise, very high attenuation can leave someone unable to hear an approaching forklift or a shouted warning.

It also encourages removal, and an earplug taken out for a conversation protects nothing.

Protection should be matched to the measured noise rather than chosen at the highest number available.

Level-dependent and electronic products exist specifically for environments where communication matters.

Rating schemes and how they are applied differ between markets, so local guidance governs the selection.

Most, but not all - canal size and shape vary enough that some people cannot achieve a seal.

Very small canals may not accept a standard plug at correct depth.

Very large canals may not be sealed by a standard plug's expansion.

Plugs are available in more than one size, which is often overlooked when a single type is issued site-wide.

Anyone who cannot achieve a comfortable seal should be offered an alternative rather than persuaded.

Custom-moulded plugs are the answer where an individual genuinely cannot be fitted by standard products.

Where plugs are removed and refitted repeatedly, yes - though the cord introduces its own considerations.

A cord keeps the pair together and off the floor between uses.

That makes them far more likely to be refitted rather than replaced or discarded.

In food and pharmaceutical environments, detectable corded plugs help with foreign body control.

Around rotating machinery a cord is a snagging risk and uncorded plugs are preferred.

The choice follows the environment rather than being a general preference.

In dispensers at the point of use, so a clean pair is always available where they are needed.

Plugs kept in a store room are not worn, because fetching them takes longer than the task.

Wall dispensers at entrances to noisy areas are the standard arrangement.

Refill discipline matters: an empty dispenser trains people that protection is unavailable.

Individually wrapped plugs keep better in dirty environments than loose ones.

Making the correct behaviour easier than the incorrect one does more than any instruction.