* Testing conducted by Bose in June 2023 using production-representative Bose QuietComfort Ultra Earbuds and a variety of music tracks using A2DP Bluetooth audio streaming at a RSSI signal strength of 75 dBm. Volume set to a playback loudness of 75 dB, 3-band EQ set to zero, in Quiet Mode (full noise cancellation). With Immersive Audio off, playback time was up to 6 hours before battery depletion. With Immersive Audio on, playback time was up to 4 hours before battery depletion. Battery life varies based on settings and usage.
** Testing conducted by Bose in July 2023 by inserting production-representative Bose QuietComfort Ultra Earbuds with battery depleted (to the point of no audio playback) into a fully charged Bose QuietComfort Ultra Earbuds charging case and charging earbuds to 100%, then resuming audio playback until battery depletion. Testing resulted in three (3) complete charging cycles by the case before a full charge was no longer possible.
*** Testing conducted by Bose in July 2023 using production-representative Bose QuietComfort Ultra Earbuds and Bose QuietComfort Ultra Earbuds charging case. Quick charge testing consisted of inserting earbuds with battery depleted (to the point of no audio playback) into a fully charged case and charging earbuds for 20 minutes, then resuming Bluetooth A2DP audio playback with volume set to loudness of 75 dB, 3-band EQ set to zero, in Quiet Mode (full noise cancellation) with Immersive Audio switched off, resulting in up to 2 hours of playback time before battery depletion.
Time to achieve fully charged earbuds was determined by inserting earbuds with battery depleted (to the point of no audio playback) into a fully charged case and charging earbuds to 100% battery charge.
