Today however, higher-priced sneakers have air bags in the soles to cushion the high and low impacts of exercise. Unlike the air bags in cars, however, these running shoe air bags are already of course inflated. When they break, they can cause sneakers - even ones that are still brand new - to squeak as noisily as when the wearer is stopping and turning on a hardwood basketball or squash court surface.
In some cases, also, it's not that the air bag(s) in the shoe sole has broken but rather that it is itself rubbing against some other material that has come loose. Nike Air shoes take their name from the fact that they are built around these airbags. Some lines or year-make model product runs have proved among runners to be particularly defective, hence adding poor workmanship to the list of reasons why a pair of today's shoes might squeak.
There is much discussion on the Internet about ways to combat the squeaky rubbing together of leather components, soles and bases, or air bags and miscellaneous sole construction components. One list for example repeats the oft-written claim that the hairspray brand Alberto VO5 can help. Other home remedies for squeaky shoes include baby powder as well as drilling several tiny holes into the sole itself.
If the pair of shoes is particularly expensive or sentimentally valuable, a repair shop can in some cases help get rid of the problem, especially if the squeakiness comes from a worn down sole or loose shank. But in most cases, the root cause and root cure for shoe squeak is an inexact science. In some cases, the noise may disappear as suddenly as it originally began.