Process
and system for inserting digital information in an audio signal and
getting them back after transmission through a reverberating channel
Keywords: audio watermarking - marking technique -
inaudible audio signal - audience measurement -
General Description
This patented technology is a digital information coding-decoding process
and system for data embedded in an audio frequency signal.
Data are inaudible and can be retrieved after a transmission through
the acoustic channel.
Within the framework of specific applications to the needs of audience
measurement services for example, it becomes necessary to conceive a
system capable of transmitting inaudible data embedded into an audiofrequency
signal, and able to decode them using a portable receiver which can
be localized inside a vehicle in a particularly noisy environment.
The data signal insertion and extraction modes into the audiofrequency
signal is based on a previous work and includes some new features.
The process runs a spread spectrum technique associated to a n-ary coding
which allows on one hand to adapt the reception and decoding system
to the acoustic channel and on the other hand to increase the usable
data rate which can be transmitted.
The main innovative aspects are
- The originality of the process is to allow the decoding of data inserted
in an inaudible way into an audio signal even when this audio signal
is transmitted through an acoustic channel.
This means that the audio signal, into which the data were beforehand
embedded, can be broadcasted by a loudspeaker, recovered by means of
a microphone and processed in order to decode the inserted data.
- The "electric connection" between the audio signal and the decoder
is not necessary anymore.
Application
This marking technique, which consists in inserting inaudible and permanent
signature inside a sound, can be used in cases such as the identification
of a program in order to control signal distribution, a particular message
in a broadcast program (advertisement, jingle, announcement) or to make
a control of a security and warning message for legal proof for instance.
Type of collaboration sought:
Licence agreement
Intellectual Property Rights:
Patent granted
Type of partner:
content provider, electronic field, legal right management agency
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