The Voice Detect Bock is useful in the following applications:
The Voice Detect block toggles an Active/Inactive read-only toggle control based on detected voice input and/or the value of a logic input from a momentary or toggle control linked to the Force Trigger toggle control. Once triggered, Active/Inactive remains TRUE until the block no longer detects voice input, Force Trigger is no longer true and the Hold Time has expired. For paging or prerecorded announcements, Active/Inactive may be linked to a Halogen Paging Station Block push-to-talk control, which in turn, initiates a page.
Use cases that highlight the capabilities of the Voice Detect Block are as follows:
See: Paging Station
See: Paging Manager
See: Paging Zone
|Input node||Connection point for wiring an input to the Voice Detect Block. This is where you connect the page or announcement signal source that you want to detect.|
Connection point for wiring output from the Voice Detect Block. This signal is delayed 0 ms to 250 ms (user setable) so that detection always precedes voice transmission. Typically this output is connected to a Paging Station input.
note: Except for the delay, the audio passes from the Input to the Output node unchanged.
Active TRUE linkable logic input that triggers the block into the Active state when checked (TRUE). The input may be momentary or latching.
When triggered, the Active/Inactive toggle control becomes TRUE, which persists until Force Trigger is unchecked (FALSE), the input voice detect signal is below Threshold and Hold Time is expired.
Active TRUE linkable logic read-only toggle output. This control is TRUE (toggle checked) when Force Trigger is TRUE, when the input voice detect signal is above Threshold or when Hold Time has not expired.
The control is FALSE (toggle unchecked) when Force Trigger is FALSE (unchecked), the input voice detect signal is below Threshold, and Hold Time is expired.
This control is typically linked to the Talk toggle control in a Halogen Paging Station block.
|Low-cut||Allows you to limit low frequencies to those of interest. This improves threshold detection. Range is 40 Hz to 400 Hz. 100 Hz is a typical setting for voice detection. (Default 100 Hz)|
Allows you to limit high frequencies to those of interest. This improves threshold detection. Range is 400 Hz to 4 kHz. 3 kHz is a typical setting for voice detection. (Default 3 kHz)
|Threshold||The Threshold control sets the level above which the detector is active. This should be set as high as possible to prevent false triggering. The Look-ahead Delay allows setting a higher threshold. Low-cut and high-cut filters limit sensitivity to frequencies of interest. Control range is -85 dBFS to 0 dBFS. A Typical setting for voice is -30 dBFS. (Default -30 dBFS)|
|Hold Time||Hold Time sets the length of time the Active/Inactive toggle remains TRUE (toggle checked) after Force Trigger becomes FALSE (unchecked) and the input detected signal goes below threshold. This allows pauses in speech without terminating a page. Control range is 1-60 seconds. A typical setting for voice is 3-4 seconds. (Default 3 seconds)|
|Look-ahead Delay Time||The Delay time sets how long the signal is delayed before being passed out of the Voice Detect block. This allows the detector to sense speech ahead of time to ensure that no speech is lost. Control range is 0 ms to 250 ms with a resolution of 21 us. A typical setting for paging is 20 ms. (Default 20 ms)|
|Detect Threshold Meter||Assists setting the threshold by showing the detected signal level relative to the set Threshold. This meter is located after the low-cut and high-cut filters and accurately shows what the detector is responding to.|