void flush ();
void make_audio_mapping_default (AudioMapping& mapping) const;
std::vector<std::string> input_names () const;
void flush ();
void make_audio_mapping_default (AudioMapping& mapping) const;
std::vector<std::string> input_names () const;
BandPassAudioFilter _left;
BandPassAudioFilter _right;
BandPassAudioFilter _centre;
BandPassAudioFilter _left;
BandPassAudioFilter _right;
BandPassAudioFilter _centre;