Infurture H1 Bedienungsanleitung Seite 8

Step4：

Your headphone can only play music on one mobile device at a time.
To play from another connected device, pause the currently active
device first.
Active Noise Cancellation
Push the ANC button to the other side to turn on Active Noise Cancellation
ANC: Blocks most low frequency noise（For example, the engine sounds of
airplanes and cars, and a few background sounds of offices）
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