Ampcontrol VAA, User Manual

Page: 53 / 81

VOICECOM USER MANUAL ISSUE 4
-51-
example, a 10 second audio sample recorded at 16bit 44kHz will take up approximately 860kBytes of memory. Table
17, below, shows the audio sample rates compatible w
it
h the Message Bank Editor and how they equate to the
maximum total message bank length.
Table 17 - Voice Message Bank Audio Format Settings
Format (Resolution and
Sample Rate)
Maximum Total Message Bank
Capacity (seconds)
Relative Audio Quality
16bit 44kHz 190 CD audio
8bit μLaw 44kHz 380
8bit μLaw 22kHz 760
8bit μLaw 11kHz 1520 AM radio
As recommended in the previous section, voice messages should be recorded and saved at 16bit 44kHz. The
Message Bank Editor allows you to lower the audio quality of the imported audio sample by changing the Format
setting as necessary. Lowering the audio quality makes the audio message smaller, thus saving memory. This
process only affects how the message is played by the VCA. The original audio format of an imported audio file is not
lost and can be restored at any time by opening the Format menu and choosing the highest resolution and sample
rate. The Format selection only affects the audio quality and hence the file size of the audio message that is
downloaded into the VCA.
NOTE: If an audio message is recorded and saved as an 8bit 22kHz WAV audio file and then imported into the
Message Bank, then 8bit 22kHz is the highest quality format that can be chosen.
As more messages are added to the Message Bank, you may find that you become short on memory space. At this
point you may have to start experimenting with the audio formats to free up Message Bank memory.
TIP: You can test an audio message by playing it from within the Voice Message Bank Editor. Select the message
number and then from the Message menu select Play. Clicking the right mouse button over the message number
opens a pop up menu that also has the Play option. By playing the message, the effect of changing the audio format
can be heard.
Pretone
The Pretone drop down menu allows the user to select tones that sound before ( pre-tone )
and after ( end-tone ) a voice message. A number of different pre and end-tone
combinations can be chosen as shown in Table 108. Pre and end-tones are made up of
three tones played in rapid succession. These tones can be used to distinguish high priority
voice messages from standard messages.
TIP: You can opt to have no pre-tone and have and end-tone (selection 7), or have a pre-
tone and no end-tone (selection 14) or no pre or end-tone at all (selection 15). Using a PLC
to control voice messages means that multiple messages can be linked together, for
example, “Pullkey tripped at” being one message and “Cut through 1”, being another message. In this instance you
would not want an end-tone after the first message and a pre-tone at the beginning of the second messages so that
the messages play seamlessly.
Table 108 - Pre and End-tone Combinations
Pretone
Number Pre-tone
Frequencies (Hz)
End-tone
Frequencies (Hz)
VCA Display
0 508, 724, 1016 1563, 1563
Pre-0, +End
1 1016, 724, 508 1563, 1563 Pre-1, +End
2 508, 508, 508 1563, 1563 Pre-2, +End
3 1250,742, 1250 1563, 1563
Pre-3, +End
4 508, 724, 1016 1563, 1563
Pre-4, +End
5 508, 724, 1016 1563, 1563 Pre-5, +End