Reading and processing of audio information reproduced from Edison phonograph cylinders by method of laser interferometry

The types of distortions present in audio signals reproduced from Edison phonograph cylinders are considered and classified. An effective approach and algorithm for processing of obtained audio information is proposed. It is shown that the use of a sound signal with frequency range up to 20 KHz at processing has two obvious advantages. The first one allowed to retain the highest harmonics of a sound signal which are not perceived directly by ear, but have a positive influence on the formation of a common sound picture. The second one - in this signal it is more convenient to remove pulse interference (clicks, crackling), since the pulse fronts are steeper and the probability of their detection is increased.