Method for tuning a noise cancellation enabled audio system and noise cancellation enabled audio system

A noise cancellation enabled audio system with an audio processor and an ear mountable playback device comprising a speaker and a feedforward microphone, the audio system being configured to be operated in a regular mode of operation and in a calibration mode of operation, wherein the audio processor is configured for, in the calibration mode of operation,

• varying a parameter, which is associated with the noise cancellation at the speaker, between a plurality of settings while a test sound is played from an ambient sound source and the playback device is placed onto a measurement fixture, the speaker facing an ear canal representation of the measurement fixture and a test microphone located within the ear canal representation;
• receiving and storing a measurement signal from the test microphone at least while the parameter is varied;
• determining a power minimum in the stored measurement signal;
• and
• determining from the plurality of settings of the varied parameter a tune parameter associated with the power minimum.