PURPOSE: To prevent listening displeasure to ears by providing a control circuit permitting the replacement when the result of discrimination by a level detection circuit discriminating the quantity for a signal level of a high fidelity sound based on a prescribed level is larger and muting the high fidelity sound when smaller.

CONSTITUTION: In a dropout compensating circuit 11, a control circuit 13 is operated depending on the quantity of the signal level of the high fidelity sound just before a dropout takes place through the detection of a level detection circuit 12 if a dropout takes place in the high fidelity sound so as to select either the replacement by the normal sound or the muting. Thus, even when the normal sound is recorded automatically at a prescribed signal level by an automatic level control circuit at recording, the normal sound is replaced into the high fidelity sound only at a large signal and the high fidelity sound is muted at a small signal. Thus, the inconvenience that a large sound is mixed suddenly at small sound volume reproduction and unnatural and displeasant listening is avoided in an excellent way.