The above example should explain why IEMs are best suited for outdoor usage thanks to the excellent mechanical dampening afforded by their airtight seal. This is largely dependent on choosing the right sized ear tip though. More often than not, the average user ends with one that cannot ensure a good seal. This is mainly because the typical Indian ear auditory canal is smaller than its American or European counterpart. Using the default medium sized tip, therefore, is a bad idea for the average Indian.