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Voice Gateway Parameter Details

Cognigy Voice Gateway has many configuration settings that are controlled directly from within your Flow. These settings can be applied individually to the scopes:

  • Setting Session Parameters. Session parameters can comfortably be set with the Set Session Config Node. When executed, the settings will apply for the remainder of the session.
  • Setting Activity Parameters. Activity parameters can be set per activity/node. If, for example, barge-in is set on the Play Node, barge-in will only be activated during the execution of this Node. Therefore, the user can interrupt the AI Agent during this output but not afterward. These configurations are also available in the Say, Question, and Optional Question Nodes.

Settings

Synthesizer - Text-To-Speech

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The TTS settings can be chosen from a pre-filled dropdown for Microsoft Azure, AWS, Google, Nuance, or a custom vendor.

Parameter Type Description
TTS Vendor Dropdown Defines the desired TTS Vendor. You can select a custom vendor.
Custom (Vendor) CognigyScript Allows for specifying an TTS Vendor, which is not in the dropdown list. This option is only available on Voice Gateway. For preinstalled providers, use all lowercase letters, for example, microsoft, google, aws. For custom providers, use the name that you specified on the Speech Service page in Voice Gateway.

The Custom field appears if you selected Custom from the TTS Vendor list.
TTS Language Dropdown Defines the language of the Voice AI Agent output.
Custom (Language) CognigyScript Allows for choosing a TTS language, which is not in the dropdown list. Defines the language of the AI Agent output. The format to use depends on the TTS Vendor, for example, de-DE, fr-FR, en-US.

The Custom field appears if you selected Custom from the TTS Language list.
TTS Voice Dropdown Defines the voice that should be used for the voice AI Agent output.
Custom (Voice) CognigyScript Allows for choosing a TTS voice, which is not in the dropdown list. This setting can be the case for region-specific voices. The format to use depends on the TTS Vendor, for example, de-DE-ConradNeural.
TTS Label CognigyScript The alternative name of the vendor is the one you specify in the Voice Gateway Self-Service Portal. If you have created multiple speech services from the same vendor, use the label to specify which service to use.
Enable Advanced TTS Config Toggle Enables the addition of a URL for an Azure Custom Voice Endpoint.
Disable TTS Audio Caching Toggle Disables TTS audio caching.

By default, the setting is deactivated. In this case, previously requested TTS audio results are stored in the AI Agent cache. When a new TTS request is made, and the audio text has been previously requested, the AI Agent retrieves the cached result instead of sending another request to the TTS provider.

When the setting is activated, the AI Agent no longer caches TTS results. In this case, each request is directly sent to your speech provider.

Note that disabling caching can increase TTS costs. For detailed information, contact your speech provider.

Recognizer - Speech-To-Text

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The STT settings can be chosen from a pre-filled dropdown for Microsoft Azure, AWS, Google, Nuance, Soniox, or a custom vendor.

Parameter Type Description
STT Vendor Dropdown Defines the desired STT Vendor. You can select a custom vendor.
Custom (Vendor) CognigyScript Allows for specifying an STT Vendor, which is not in the dropdown list. Select the desired STT Vendor. This option is only available on Voice Gateway. For preinstalled providers, use all lowercase letters like microsoft, google, aws. For custom providers, use the name that you specified on the Speech Service page in Voice Gateway.

The Custom field appears if you selected Custom from the STT Vendor list.
STT Language Dropdown Defines the language that should be recognized.
Custom (Language) CognigyScript Allows for choosing a STT language, which is not in the dropdown list. This setting can be the case for region-specific voices. The format to use depends on the STT Vendor, for example, de-DE, fr-FR, en-US.

The Custom field appears if you selected Custom from the STT Language list.
Deepgram Model Dropdown This parameter is active only when Deepgram is selected in the STT Vendor setting.

Choose a model for processing submitted audio. Each model is associated with a tier. Ensure that the selected tier is available for the chosen STT language. For detailed information about Deepgram models, refer to the Deepgram documentation.
Endpointing Toggle This parameter is active only when Deepgram is selected in the STT Vendor setting.

Deepgram's Endpointing feature watches streaming audio for long pauses that signal the end of speech. When it spots an endpoint, it finalizes predictions and returns the transcript, marking it as complete with the speech_final parameter set to true. For detailed information about Deepgram Endpointing, refer to the Deepgram documentation.

The duration for detecting the end of speech is preconfigured with a default value (10 milliseconds). If you want to change this value, use the Endpointing Time setting.
Endpointing Time Number This parameter is active only when Deepgram is selected in the STT Vendor setting and the Endpointing toggle is enabled.

Customize the duration (in milliseconds) for detecting the end of speech. The default is 10 milliseconds of silence. Transcripts are sent after detecting silence, and the system waits until the speaker resumes or the required silence time is reached. Once either condition is met, a transcript is sent back with speech_final set to true.
Smart Formatting Toggle This parameter is active only when Deepgram is selected in the STT Vendor setting.

Deepgram's Smart Format feature applies additional formatting to transcripts to optimize them for human readability. Smart Format capabilities vary between models. When Smart Formatting is turned on, Deepgram will always apply the best-available formatting for your chosen model, tier, and language combination. For detailed examples, refer to the Deepgram documentation.

Note that when Smart Formatting is turned on, punctuation will be activated, even if you have the Disable STT Punctuation setting enabled.
STT Hints Text Array of words or phrases to assist speech detection. If you want to use multiple hints, enter each hint into a separate input field. For instance, you can enter Germany in the first field, France in the second field, and Netherlands in the third field. The STT provider will receive the data in array format: ["Germany", "France", "Netherlands"].
Note: This requires support from the STT engine. The field is not available for the Nuance speech vendor.
Dynamic Hints CognigyScript Uses context or input for adding array hints. For example, {{context.hints}} or {{input.hints}}. You can override these settings using Advanced parameters.
STT Label CognigyScript The alternative name of the vendor is the one you specify in the Voice Gateway Self-Service Portal. If you have created multiple speech services from the same vendor, use the label to specify which service to use.
Google Model Dropdown This parameter is active only when Google is selected in the STT Vendor setting.

Utilizes one of Google Cloud Speech-to-Text transcription models, with the latest_short model being the default choice. For a detailed list of Google models, refer to the Transcription models section in the Google Documentation. Keep in mind that the default value is a Google Model type that can be used if other models don't suit your specific scenario.
Enable Voice Activity Detection Toggle Delays connection to cloud recognizer until the speech is detected.
VAD Sensitivity Slider Detection sensitivity, the lowest value has the highest sensitivity.
Minimal Voice Duration Slider Milliseconds of speech activity required before connecting to the cloud recognizer.
Disable STT Punctuation Toggle This parameter is active only when Google or Deepgram is selected in the STT Vendor setting.

Prevents the STT response from the AI Agent to include punctuation marks.
Enable Advanced TTS Config Toggle Enables the addition of an ID for an Azure's Custom Speech model deployment.
Enable Audio Logging Toggle Enables recording and logging of audio from the user on Azure.
Recognize Language Toggle Enables the addition of alternative languages for recognition. You can select a maximum of 3 languages. To reuse these languages in other Nodes, such as the child Nodes of the Lookup Node, use the following format: de-DE, fr-FR, en-US. For the parent Node of the Lookup Node, specify input.data.payload.speech.language_code.

Barge In

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Warning

Enabled Barge-In uses the TTS and SST vendor to listen throughout the entire conversation. Consequently, Barge-In may lead to increased subscription costs with your vendor.

Barge In is a feature that allows the caller to interrupt the voice AI Agent by using speech input or DTMF digits during the entire call. By default, this feature is turned off.

Before release 4.80, this feature could not be controlled when the call was transferred to the contact center. Barge In was always active, allowing the caller to interrupt the voice AI Agent at any time.

Starting with release 4.80, you can enable or disable Barge In when the call is redirected to the contact center. This improvement lets you decide whether the caller should listen to the voice AI Agent's messages fully or have the option to interrupt them. This way, the caller can't use Barge In to skip, for example, important legal information such as the GDPR.

To ensure Barge In works correctly after the call is transferred to the contact center, place the Set Session Config Node above the Handover to Agent Node.

Parameter Type Description
Barge In On Speech Toggle Enables interrupting the voice AI Agent with speech. The user is able to interrupt the voice AI Agent's responses even after the handover has taken place and a human agent communicates with the user through Text-To-Speech. This parameter is disabled by default. It will retain its setting throughout the whole conversation.
Barge In On DTMF Toggle Enables interrupting the voice AI Agent with DTMF digits. The user is able to interrupt the voice AI Agent's responses by pressing any digit, even after the handover has taken place and a human agent communicates with the user through Text-To-Speech. This parameter is disabled by default. It will retain its setting throughout the whole conversation.
Barge In Minimum Words Slider Defines the minimum number of words that the user must say for the Voice Gateway to consider it a barge-in.

User Input Timeout

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This feature defines what should happen when there is no input from the user.

Before the release 4.81, User Input Timeout was always enabled and users had to determine the number of milliseconds before timeout occurred. Starting from release 4.81, users can enable or disable User Input Timeout using a toggle. This setting keeps the voice AI Agent on the call even if the caller takes a while to respond. When the User Input Timeout is disabled, the voice AI Agent will wait for the caller's response.

Parameter Type Description
Enable User No Input Timeout Toggle Enables or disables the User No Input Timeout parameter. This parameter is enabled by default.
User No Input Mode Dropdown This parameter is active only when Enable User No Input Timeout is enabled.

Defines the action if a user does not provide an input to the AI Agent in time.
User No Input Timeout Number This parameter is active only when Enable User No Input Timeout is enabled.

Defines the timeout duration for user input, specified in milliseconds (ms).
User No Input Retries Number This parameter is active only when Enable User No Input Timeout is enabled.

Defines how often the voice AI Agent should retry to get an input from a user before completing the call.

DTMF

Enables DTMF collection.

Parameter Type Description
Capture DTMF signals Toggle Enables capturing DTMF signals by the AI Agent.
DTMF Inter Digit Timeout Number Defines the timeout between collected DTMF digits.
DTMF Max Digits Number Defines the maximum number of digits the user can enter. The digits are submitted automatically once this limit is reached.
DTMF Min Digits Number Defines the minimum number of digits before they are forwarded to the AI Agent. A submit digit can override this.
DTMF Submit Digit CognigyScript Defines the DTMF submit digit, which is used for submitting the previously entered digits. This action overrides the minimum digits validation.

Continuous ASR

Continuous ASR enables the Voice Gateway to concatenate multiple STT recognitions of the user and then send them as a single textual message to the AI Agent.

Parameter Type Description
Enable Continuous ASR Toggle Enable or disable Continuous ASR.
Continuous ASR Submit Digit CognigyScript Defines a special DTMF key, which sends the accumulated recognitions to the flow.
Continuous ASR Timeout Number Defines the number of milliseconds of silence before the accumulated recognitions are sent to the flow.

Atmosphere Sounds

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This feature is useful in scenarios where users interact with an AI Agent instead of a human when calling the contact center. Within the Atmosphere Sound section, you can configure the MP3 background track. This track may include office noises or other sounds that simulate human interaction, helping the caller feel they are speaking with a person rather than an AI Agent. Playing a background MP3 track during the conversation with AI Agents makes it more engaging and personalized.

The track plays during the conversation with the AI Agent, continues when the call is transferred to a human agent, and stops once the human agent accepts the call.

Parameter Type Description
Action Dropdown Selects an action to play, silence, or remove the track:
- play - plays the track in the background.
- silence - mutes the track.
- remove - removes the track from the background completely.
URL Text Accepts direct URL links to MP3 tracks, for example, https://abc.xyz/music.mp3.
Loop Toggle Turns on looping for the audio track
Volume Number Adjusts the volume of the track. Can be set from -50 to +50 dB. The default value is 0, meaning that the track is played as-is, with no adjustments to its volume. Users may need to adjust the volume by testing the call and checking if the Atmosphere Sounds track is neither too loud nor too quiet.

Silence Overlay

Silence Overlay enables you to play an MP3 file in the background during calls with an AI Agent. This feature is activated during prolonged periods of silence, which may result from the AI Agent's background activity. Playing the track informs the customer that the AI Agent is processing their query, which may take some time. The Silence Overlay track can simulate office sounds, for example, a human agent typing on a keyboard and clicking the mouse.

When Silence Overlay is enabled in the Set Session Config Node, the Silence Overlay track starts playing automatically once the AI Agent takes longer to respond, then stops the moment the AI Agent responds. You can adjust the delay before the Silence Overlay starts to make it sound more natural.

If you enabled the Call Recording feature in the Voice Gateway Self-Service Portal, the Silence Overlay track is recorded together with the AI Agent's track and can be played back in the audio file.

Parameter Type Description
Action Dropdown Defines an action to play or remove the track:
- play - plays the track in the background when prolonged silence occurs.
- remove - removes the track from the conversation. Next time a prolonged silence occurs, the Silence Overlay will not play.
Make sure to place the next Set Session Config Node before the Node that needs to have Silence Overlay removed.
URL Text Accepts a direct URL link to an MP3 track, for example, https://abc.xyz/music.mp3. This parameter appears when the play action is selected.
Delay for starting the Silence Overlay Number Defines the wait time before the MP3 track plays, simulating a humanlike response. For example, human agents often have a pause between speaking and typing. This parameter appears when the play action is selected.

Advanced

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Parameter Type Description
Additional Session Parameters JSON Allows for configuring settings using JSON. If you have already made changes using the UI settings above, this field will overwrite them. Also, you can specify additional parameters in the JSON, which are unavailable in the UI, such as vendor credentials.

If you want to specify a custom TTS or STT provider in the vendor parameter, use the custom:<provider-name> format, for example, "vendor": "custom:My Speech provider".

JSON example:

{
  "synthesizer": {
    "vendor": "microsoft",
    "language": "de-DE",
    "voice": "en-US-JennyNeural"
  },
  "recognizer": {
    "vendor": "google",
    "language": "de-DE",
    "hints": [
      "help",
      "skip",
      "confirm"
    ],
    "hintBoost": 20
  }
}