Task 1: Read and translate the text in written form

The Audio System 
The audio system has four major components: one or more microphones (and 
mixer if required); the loudspeaker system; the video codec and digital phone 
hybrid that handles the signal processing allowing full duplex (two way) 
conversation and transmission/reception of the signals; and the acoustic echo 
cancellation (to prevent the source station hearing itself amplified and re-
transmitted from the receive location). The performance of the entire audio chain is 
directly tied to the room acoustics. The performance of the echo cancelling is 
directly tied to the decay of sound in the room, and the quality of microphone 
pickup is likewise affected by early reflections and reverberation. This is the 
reason we emphasize the importance of room acoustics as part of the system 
design. 
Microphone placement plays an important part of the sense of distance between the 
talker and the receiving station. We are all familiar with the "group of people in a 
barrel" sound of a speaker phone. The speaker-phone sound results from a 
combination of an omni-directional microphone and hard surfaces in the room. The 
way to beat that tell-tale sound quality is by using appropriate microphones, getting 
the microphone closer to the talkers in the source room, and controlling the 
reflections from hard walls. This can help make a video conference sound like a 
cross-the-table meeting. 
The Control System 
The control of the electronics associated with an elaborate video conference system 
can become cumbersome as the complexity of the system increases. Where a 
permanently installed video conference system is used, the control of lights, 
drapery, video and audio equipment becomes more complicated and 
interconnected. An integrated control system provides ready access to controls that 
are located in an equipment room, or simultaneously activates several related 
controls in the appropriate sequence. It can control cameras, switching, routing, 
and even video preview or cue monitoring when a colour touch screen control 
device is used. A touch screen interface has a major advantage in that it can be 
programmed in more than one language, and can be programmed to describe the 

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functions in plain language. This reduces the learning curve, and the intimidation 
presented by high tech equipment. Where the proper communication protocols are 
available the control of the cameras and audio at the other station is possible.