Philips HD 1500 Mode D'emploi page 10

XP SBC HD 1500/17 for USA 14-01-2004 13:34 Pagina 10
10 ENGLISH
If we wish to reproduce all those effects through an audio system, than we
need to take IID, ITD, pinna effects, room impulse response, etc. into
account.That is where Head-Related Transfer Functions (HRTF) come into
play.
An HRTF is a mathematical equation that describes how a sound is effected
when travelling from its source to our ears.
There are several ways to synthesise an HRTF.The most common way to
measure an HRTF makes use of placing tiny microphones in a listener's ears.
Every person has its unique HRTF. However, we can identify crucial parts in
an HRTF that are responsible for localization of sound as if this sound
would be radiated by a typical home cinema speaker set-up. When these
parts are synthesized in an optimal way, a typical 5 speaker set-up listening
experience is created.
HRTFs are implemented in real-time Digital Signal Processors (DSP) and
will then be applied to audio signals in order to reproduce "spatial" cues, i.e.
create a sense of directionality.
It is through these techniques that Philips is able to bring you a home
cinema experience through a headphone that is as real as when you would
be listening to an actual 5.1 speaker set-up.
Philips patent pending digital wireless audio
technology (EDAL)
The Enhanced Digital wireless Audio Link (EDAL) is a Philips patent pending
technology offering a wireless audio connection with digital quality
specification.The digital audio link has an improved robustness compared to
analogue wireless FM systems and is further characterised by its low power
design. Low latency audio-transport coding prevents lip-sync problems
which ensures that audio and picture remain synchronized so that for
example a movie actor's lip movements will coincide with what you are
actually hearing.