When analogue sound is converted into a digital format the first big step has been achieved. In many cases this may be sufficient. But there might be situations where this is not enough. A historic recording or a cassette tape may not be appreciated as it is. There could have been bad microphone conditions so voices are unclear and the spoken words are not understandable. There are many reasons to improve the result. It may be complicated. Which strategy should be used. Which software will be the right for the purpose and what other measures should be applied?
Sound restoration can be easy in some cases. Sometimes it can be rather complicated. Therefore there is no fixed pricing. All will depend on an assessment of the concrete material. But good results can come out of a restoration. Try for example to listen the box set Lauritz Melchior at his best. Issued by the Hegermann-Lindencrone Udgiverselskabet with sound restored by Hein Information Tools.