TechniSat TECHNIRADIO 3 Instruction Manual page 94

7 DAB+ (digital radio) function
7.1 What is DAB+?
DAB+ is a new digital format through which crystal clear sound with no noise can
be heard. In contrast to conventional analogue radio stations, DAB+ can be used to
broadcast multiple stations on one and the same frequency. This is referred to as an
ensemble or multiplex. An ensemble is comprised of the radio station, as well as several
service components or data services which are broadcast individually by the radio
stations. For further information, please visit e.g. www.dabplus.de or www.dabplus.ch.
7.1.1 Data compression
By doing so, digital radio takes advantage of the properties of human hearing. The
human ear does not perceive sounds under a specific minimum volume. Data under the
so-called audibility threshold can, therefore, be filtered out. This is possible since, within
a digital data stream, the relevant relative volume for other units is saved for every unit
of information. Moreover, at a specific theshold, the quieter parts within an audio signal
are blocked out by the louder parts. All the sound information below the threshold
of hearing in a piece of music can be filtered out of the signal to be broadcast. This
leads to a reduction of data in the data stream to be transmitted, with no perceptible
difference in sound for the listener (HE AAC v2 process as a supplementary codification
process for DAB+).
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