I'm often asked if memory foam is a better alternative to silicone ear tips for earphones.  Since we sell both and the price difference is nominal, I think the following is pretty objective.  Either type of ear tip will isolate sound very well, but I only wear our memory foam earbud tips now and have since the day we started producing them.  Simply put, they are my preference because I find them to be more comfortable.  You simply compresses them between three fingers so they form somewhat of a cone shape and insert them in the ear.  In a couple moments they try to expand back to shape but can't do so fully, so they fill the voids between them and your ear canal wall.  This phenomena creates a perfect seal which is necessary in isolating the sound of your earbud so you can hear every note of your favorite music.  I think this feature contributes to them staying in your ears better too, but I never had a problem with a silicone tip staying in my ear during use.  They did move a little on occassion, but for me that wasn't the big deal it is for other people, runners for example.  Silicone isolates just as well in my book, so I can't tell you one is better than the other in that regard either.  Memory foam tips come in 3 sizes (and the connection hole is not universal so be sure to determine what size your earphones will require or ask us) where some silicone tips are available in up to five size to achieve the best fit.  Just remember, they too do not have a universal connection either so you have to verify compatibility.  That leaves durability as the lone feature where I think a difference exists.  Silicone tips are virtually indistructable and can be washed easily so they win this match up.  Also, memory foam tips are known to deteriorate over time and can be washed, but they have to dry completely before use.  Alot of the deterioration comes from user abuse.  I would argue all of it does because I have yet to encounter one of mine tearing or deteriorating.  I really can't figure out why people have this issue.  I use my earphones at the gym 3 to 4 days a week and then put my earphones in a case when I'm not using them and have yet needed to replace a memory foam tip due to it deteriorating.  I don't wash mine, but I could using warm water and then let them dry over night.  Instead I just put new ones on when I see they are getting dirty.  After all, I only have about 50000 of them on hand all the time!  So, memory foam vs silicone earbud tips?  I like memory foam best, but if you are unsure just ask us to split your order and get 3 pairs of each style and decide for yourself.  We're happy to do so.