With the Sennheiser Momentum 4 headphones, active noise cancellation (ANC) cannot be completely deactivated while they are being used in active mode. Instead, you can switch between different ANC settings, including a transparency mode that allows ambient noise to pass through.

The ANC function can be customised via the Sennheiser Smart Control app, where users can choose between adaptive ANC and transparency mode. However, there is no option to switch off ANC completely when the headphones are active. To use the headphones without digital EQ settings, you would have to switch them off and use a cable.