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 JBL Signature Sound: Nothing beats incredibly clear music and calls from 11mm dynamic drivers powered by JBL Signature Sound. True Adaptive Noise Cancelling with Smart Ambient: True Adaptive Noise Cancelling automatically adjusts to your surroundings, eliminating distractions for better sound wherever you are. Or use Smart Ambient when you need to focus on your environment, all without removing your earbuds. 40 (10+30) hours of playback with wireless charging: Never miss a moment with 40 hours of Qi-compatible battery life (including 10 hours in the earbuds + 30 hours in the case). Need a boost. Just 15 minutes of Speed Charge gives you another four hours of playtime—fast. 6 mics for perfect calls with zero noise: Six beamforming microphones reduce wind and noise interference so your words always come through loud and clear. And with Voice Aware, you can choose how much of your own voice to hear by controlling the amount of mic input routed back into your earbuds. Oval Tubist for better comfort, isolation and bass: Better shape, better sound. That's why JBL designed these headphones with Oval Tubist and oval silicon tips for a perfectly snug fit. The stick closed design with oval tubes ensure better noise cancellation and enhanced audio quality for those who prefer a cleaner aesthetic.