Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
This is a decent pair of earphones. I have small ears but the smallest sized earplugs fit well, and they don't drop out even when I'm jogging. The "hear-through" function is pretty genius. The only complaint for now would be the carrying case - the cap is somewhat tough to open and the hinge looks fragile, so I'm not sure how long it will last before the cap breaks off.