Most disposable hearing protection comes in the form of ear plugs.
These are made primarily out of foam, and can be cut by machines very quickly.
I know that I regularly purchase a pack of 500 pairs of ear plugs which are disposable for fewer than 70 dollars.
You can get these from a number of hardware stores and if you buy in bulk then you will save a huge amount of money.
These earplugs are very simple to use.
All you need to do is roll them in your fingers so that the diameter of the foam is quite small, and then push them into the shaft of your ear.
Be very careful that you don't push them in too far, or they can be hard to get out.
Just let the foam expand slowly, and you will find that the noise level drops considerably.
A lot of people use custom made earplugs, but these are expensive and you can't even afford to damage them.
The foam ear plugs can be dispensed by winding a handle on a small dispenser, which is perfect in the workplace environment.
You can purchase cheap, disposable ear muffs but they really aren't worth it.
What it comes down to is that if foam earplugs work you should use them because they are cheap and comfortable.
If the noise is above the rating of the earplugs then you should be looking into something else, regardless of whether that costs you some extra money.
Your hearing can't be replaced; so even if you have to spend a few hundred dollars to look after it you will thank yourself in many years to come!