(57) The invention relates to a receiver of a transmission wave in which a specific information data signal and its validity identification data signal are transmitted by the same frequency band, in which the receiver desirably reproduces specific information only in a situation where the specific information can be truly reproduced in the reception system. A demodulating unit (31 to 36) receives the transmission wave and demodulates it to a predetermined digital signal. A decoding unit (38 and 40) decodes the digital signal, and a detecting unit 3B obtains an error amount of the digital signal recognized in the decoding process. An evaluating unit 3B evaluates the error amount, and a detecting unit 3A detects an identification data signal from a decoded output. The control part 3C (30) reproduces and outputs the specific information data signal concerning the identification data signal based on the evaluation result and the identification data signal. Even when a code rate of the specific information data signal to be information reproduced differs from that of the validity identification data signal, the specific data signal can be desirably information reproduced at a proper timing. The invention also relates to a digital audio signal receiver having a muting function for a reproduction audio sound and accomplishing a good muting operation even for a digital audio signal having no error detection code. A control part (30) obtains an error amount of a digital signal to be recognized in the decoding process and a muting block (42) effects the muting of an audio signal to be reproduced based on the digital signal at a muting level according to the error amount.