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Properties : Telephone Device

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Telephone Device

Property Description
Driver Here you choose the direct access or the TAPI mode of modem communication. To learn more about communication modes, please read F.A.Q. #21.
Modem Select your modem from the list.
COM port number This is usually COM port 1-4.

Advanced Properties

Option Values Description
Silence Detection Hangs up if a specified duration of silence is detected.
  • Sensitivity
0 - 100% min
The least sensitive setting. Least likely to detect periods of silence, but is still able to do so, if the line is really quiet. <midrange value>
An exact value; midrange setting. Likely to be the best overall compromise on normal telephone lines.

The most sensitive setting. Most likely to detect even brief periods of silence.

  • Period
Measured in seconds. Default is 5 seconds. Silence detection period, seconds. When no voice is present in the line for a specified period, the program assumes silence and hangs up.
Use hardware gain control (AGC) Disabled by default Allow modem hardware to perform Automatic Gain Control to adjust the voice volume to a standard level. Please note that many modems have no AGC at all, while some other modems do not allow it to be turned off.
Use software gain control (AGC) Enabled by default Software Automatic Gain Control adjusts the sound volume to an average level automatically. Turn it ON if sound levels are too loud or too quiet, and turn it OFF if a recorded voice is noisy. If your modem has built-in hardware AGC, you may turn this OFF.


Developer Mode

Your modem manual will indicate which types of voice compression it supports.

A variety of voice codecs are available; if garbled sounds are produced, try changing the voice compression codec.


GSM 6.10 compression is a frame-based speech codec with at least two different implementations: encapsulated GSM and un-encapsulated GSM. The GSM compression type is usually detected automatically.


Option Meaning
Compatibility option Enables short delays between commands for better compatibility.  The closer the slider is to the "compatibility" edge, the slower (but more reliable) the performance will be.

Related topics

1998 - 2002 Oleg Afonin.

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