Reducing Speech Recognition Latency Tips

Great question - push-to-talk is the best way to remove the extra latency from fixed-length recordings. You already have the right idea: use a manual start/stop so the Bing Speech skill only records while the user intends to speak. Below I outline the recommended approach (preferred), an alternative using On Variable Changed, wiring notes, Bing Speech settings to minimize latency, and links to the Synthiam docs.

Short summary

• Best approach: Add a Script robot skill (JavaScript) that watches a digital input on your EZ-B v4 and calls:
  • controlCommand("Bing Speech Recognition", "StartListening")
  • controlCommand("Bing Speech Recognition", "StopListening")
• This produces near-instant Stop transcription processing (no forced 5s max cutoff).
• See the Push-to-Talk tutorial for a full worked example: https://synthiam.com/Support/Get-Started/Tutorials/speech-recognition-with-push-button-microphone

Option A - Preferred: Script skill (push-to-talk loop)

1. Project Add robot skill Scripting Script (choose JavaScript).
2. Open the Script editor and paste this (replace d0 with the digital port you wired to):

// Push-to-talk for Bing Speech Recognition using a button on d0
// Button released = high (pulled up). Button pressed = low (to ground).
while (true) {
  // Wait for button press (low)
  Digital.wait(d0, false, 10);

  // Start Bing listening
  controlCommand("Bing Speech Recognition", "StartListening");

  // Short debounce to avoid very fast taps
  sleep(200);

  // Wait for button release (high)
  Digital.wait(d0, true, 10);

  // Stop listening and let Bing process immediately
  controlCommand("Bing Speech Recognition", "StopListening");

  // Optional small delay to avoid immediate restart
  sleep(100);
}

Notes:

• Use d0, d1, etc. as unquoted constants (do not use "d0").
• Use sleep(ms) (milliseconds) - ARC’s built-in sleep is preferred.
• The short sleep after StartListening gives the skill time to initialize for very quick taps.

Option B - Use On Variable Changed (if you already have a variable source) If your Read Digital (or external skill) sets a global variable (for example $MyButton) on press/release, you can use On Variable Changed to run a small script:

Example On Variable Changed JS script:

// This runs when $MyButton changes
var val = getVar("$MyButton");
if (val == "0" || val == 0) {
  // pressed (low)
  controlCommand("Bing Speech Recognition", "StartListening");
} else {
  // released (high)
  controlCommand("Bing Speech Recognition", "StopListening");
}

(Confirm what variable Read Digital exposes - otherwise prefer the Script skill approach.)

Wiring and hardware notes

• Use a momentary push-button wired so that:
  • Released = pulled high (to Vcc via pull-up)
  • Pressed = connects the digital port to GND (reads low)
• Typical wiring: Button between D0 and GND, plus pull-up resistor from D0 to 3.3V/5V (or enable internal pull-up if your controller supports it).
• If you want a remote (wireless) switch, use the receiver output into an EZ-B digital input the same way (or use a relay to ground the pin on press).

Bing Speech / ARC settings to reduce latency

• In the Bing Speech skill settings:
  • Turn off wake word if you will rely on push-to-talk.
  • Set the max recording length to a higher value (don’t let Bing auto-cut recording early). With push-to-talk StopListening is what ends the capture - avoid short max cutoffs that force transcription after timeout.
  • Use the skill’s All Recognized Script (or watch $BingSpeech variable) - that script runs immediately when transcription returns.
• StopListening triggers the Bing skill to send the captured audio for recognition immediately - thus Stop transcript time is much shorter than waiting for a timeout.

Other tips to improve responsiveness

• Use a wired microphone on the PC running ARC or a low-latency audio input device.
• Avoid overlapping speech while the robot is speaking; you can prevent new starts by monitoring $IsSpeaking (getVar("$IsSpeaking")).
• If you need even lower end-to-end latency, try keeping audio quality consistent (mono, 16k/16bit is typically supported) and avoid heavy CPU loads on the ARC machine.

Links

• Push-to-Talk tutorial (walkthrough + example code): https://synthiam.com/Support/Get-Started/Tutorials/speech-recognition-with-push-button-microphone
• Bing Speech skill page: open the skill settings inside ARC (Project Add robot skill Audio category Bing Speech Recognition)
• Read Digital skill doc: https://synthiam.com/Support/Skills/Digital/Read-Digital?id=16093
• On Variable Changed skill doc: https://synthiam.com/Support/Skills/Scripting/On-Variable-Changed?id=19359

Questions for you

• Which EZ-B digital port do you plan to use (d0..d23)?
• Do you want a momentary push-button (hold to talk) or a toggle button (press to start, press to stop)?
• Would you like me to make a ready-to-paste Script skill that matches your port and preferred behavior?

If you tell me the port and whether you want hold-to-talk or press-to-toggle, I’ll post the exact script and short setup steps (kebab menu settings) you can drop into your project.