Small parenthesis about watermarking

The use of this technology obliges each station or channel that wants to measure its audience to include a code in the audio signal and therefore to pay. It is strangely almost never mentioned that the recognition of watermarking signals for radio functions poorly in noisy environments (such as in cars is one of the contexts in which the hearing of terrestrial radio is still virtually not challenged by Internet). Tests conducted on these systems have noted very low rate recognition. The television people meters have an average error of 10%. And yet, in this case, the noise can not affect recognition. The individual passive people meters tested in 2009 by Rajar had a recognition rate of about 50% Large institutions heavily involved in the audiovisual media audience measurement have been converted to the virtues of watermarking, even those who had long been criticized for its lack of reliability. The individual passive audience measurement can be performed without watermarking and with fewer errors. But that choice could lose competitive advantages to the major institutions.