A Systemic Approach to the Preservation of Audio Documents: Methodology and Software Tools
Figure 2
The figure shows an example of impulsive noise (click) in the waveform of an audio signal extracted from a 78 rpm shellac disc. It is clearly visible at second 13.263. Such disturbance can be caused by a speck of dust in a disc groove. Time (seconds) is shown on the -axis; amplitude (normalized) is shown on the -axis.
