DSEE restores high frequency sounds lost in compression. Note : If the size of the earbud tips does not match the size of your ear canals or the headset is not worn properly in your ears, you may not obtain the correct sound qualities or call performance. Change the earbud tips to ones that fit more snugly in your ear. Specific uses for product : Sports and Exercise Up to 10hr battery life, total up to 20hr with charging case Splash-proof and sweat-proof with an IPX4 rating Easier, clearer hands-free calling Small and light for a great fit and all day wear Ergonomic Surface Design conforms to most ear shapes Fine-tune your sound using the Sony | Headphones Connect app Optional use of one earbud only Easy button operation to take control without your phone.