To completely mask really loud snoring (at around 75 dB) so that you cannot hear it at all, you would need to block 60 dB or more of sound if you have normal hearing -- that's around 15 dB, because 15 dB is about the volume at which people with normal hearing begin to be able to hear sound. Here is the problem: Only about 33 dB of that really loud snoring sound passes directly through the ear canal, where the earplugs can block the sound. A great deal of sound travels around the ear canal through

the bones in your head, right to the eardrum.  So even if you completely blocked your ear canals with ear plugs, which would reduce the 75 dB of the snoring sound to about 42 dB (about the level of a quiet voice), you would still be able to hear the snoring. So even with the best ear plugs available, the snoring would still be much too loud to sleep with comfortably. If you've tried ear plugs and they simply have not worked for you, this is why.  No ear plug can do the job when it comes to really loud snoring.

To summarize the point: No ear plug will ever be able to adequately block really loud snoring. To solve the really loud snoring problem, ear plugs alone just aren't enough.

The absolute threshold of human hearing is defined as 0 dB, and people with normal hearing can just begin to hear sound at 15 dB. A watch ticks at about 20 dB. A whisper is about 40 dB. A normal voice is about 55-65 dB, and really loud snoring can be as loud as 75 dB, with most snoring registering in the range of 50-70 dB. Human hearing is remarkably acute under normal circumstances, and when it's late at night and your environment is really quiet, your hearing becomes even more sensitive.

Being able to hear very low sounds is tremendously helpful... unless you are trying to sleep.  As you lie awake in the dark quiet of your bedroom, you can hear the traffic off in the distance, the ticking of a clock, the dripping of a faucet, the breathing of your sleeping partner, or the muted sound of a TV playing somewhere in the building. Because ear plugs often simply aren't effective enough, millions of people sleep with a fan, or an air purifier, or radio, or white noise machine running to mask these little noises in the night. This is called a masking noise, or a sound masker, and is usually white noise.