A method of performing in a computing device volume-levelling processing on input audio data, the method comprising: applying one or more filters to the input audio data; obtaining a value indicative of the difference between a target output loudness level and an estimated loudness level of the input audio data; and adapting the filter coefficients of the one or more filters based on a weighted version of the obtained value, starting, or stopping, the volume-levelling processing comprising: obtaining an indication to start, or stop, the volume-levelling processing; characterised in that starting, or stopping, the volume levelling processing further comprises: gradually increasing, or decreasing, the weighting of the weighted version of the obtained value, in response to obtaining the indication to start, or stop, the volume-levelling processing; when starting the volume-levelling processing, cross-fading from i) an output of a module configured to apply a substantially frequency-independent gain to the input audio data to ii) an output of the one or more filters (405, 410); and when stopping the volume-levelling processing, cross-fading from i) the output of the one or more filters to ii) the output of the module configured to apply a substantially frequency-independent gain to the input audio data. applying one or more filters to the input audio data; obtaining a value indicative of the difference between a target output loudness level and an estimated loudness level of the input audio data; and adapting the filter coefficients of the one or more filters based on a weighted version of the obtained value, starting, or stopping, the volume-levelling processing comprising: obtaining an indication to start, or stop, the volume-levelling processing; characterised in that starting, or stopping, the volume levelling processing further comprises: gradually increasing, or decreasing, the weighting of the weighted version of the obtained value, in response to obtaining the indication to start, or stop, the volume-levelling processing; when starting the volume-levelling processing, cross-fading from i) an output of a module configured to apply a substantially frequency-independent gain to the input audio data to ii) an output of the one or more filters (405, 410); and when stopping the volume-levelling processing, cross-fading from i) the output of the one or more filters to ii) the output of the module configured to apply a substantially frequency-independent gain to the input audio data. obtaining an indication to start, or stop, the volume-levelling processing; characterised in that starting, or stopping, the volume levelling processing further comprises: gradually increasing, or decreasing, the weighting of the weighted version of the obtained value, in response to obtaining the indication to start, or stop, the volume-levelling processing; when starting the volume-levelling processing, cross-fading from i) an output of a module configured to apply a substantially frequency-independent gain to the input audio data to ii) an output of the one or more filters (405, 410); and when stopping the volume-levelling processing, cross-fading from i) the output of the one or more filters to ii) the output of the module configured to apply a substantially frequency-independent gain to the input audio data. gradually increasing, or decreasing, the weighting of the weighted version of the obtained value, in response to obtaining the indication to start, or stop, the volume-levelling processing; when starting the volume-levelling processing, cross-fading from i) an output of a module configured to apply a substantially frequency-independent gain to the input audio data to ii) an output of the one or more filters (405, 410); and when stopping the volume-levelling processing, cross-fading from i) the output of the one or more filters to ii) the output of the module configured to apply a substantially frequency-independent gain to the input audio data.