_smoothing = new wxSlider (this, wxID_ANY, AudioPlot::max_smoothing / 2, 1, AudioPlot::max_smoothing);
_smoothing->Connect (wxID_ANY, wxEVT_SCROLL_THUMBTRACK, wxScrollEventHandler (AudioDialog::smoothing_changed), 0, this);
_smoothing = new wxSlider (this, wxID_ANY, AudioPlot::max_smoothing / 2, 1, AudioPlot::max_smoothing);
_smoothing->Connect (wxID_ANY, wxEVT_SCROLL_THUMBTRACK, wxScrollEventHandler (AudioDialog::smoothing_changed), 0, this);