feat: add VAD mode setting — standard vs aggressive latency

Standard: 5 ms open / 20 ms close ramp (comfortable feel)
Aggressive: 1 ms open / 5 ms close ramp (lowest possible latency)

The mode is surfaced as a radio selector in Settings → Audio → Voice
activity detection, visible while VAD is enabled. Wired through
NoiseGateParams.vadAggressive → worklet updateParams.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/livekit/NoiseGateProcessor.worklet.ts

@@ -36,6 +36,7 @@ interface NoiseGateParams {
   vadEnabled: boolean;
   vadPositiveThreshold: number; // open gate when prob >= this (0–1)
   vadNegativeThreshold: number; // close gate when prob < this (0–1)
+  vadAggressive: boolean;       // true: 1 ms open / 5 ms close; false: 5 ms / 20 ms
 }
 
 interface VADGateMessage {
@@ -209,9 +210,9 @@ class NoiseGateProcessor extends AudioWorkletProcessor {
   // VAD gate state
   private vadGateOpen = true; // starts open; TEN-VAD closes it on first silent frame
   private vadAttenuation = 1.0;
-  // Asymmetric ramp: fast open to avoid masking speech onset, slow close to de-click
-  private readonly vadOpenRampRate = 1.0 / (0.005 * sampleRate);  // 5 ms
-  private readonly vadCloseRampRate = 1.0 / (0.02 * sampleRate);  // 20 ms
+  // Asymmetric ramp rates — recomputed in updateParams based on vadAggressive
+  private vadOpenRampRate = 1.0 / (0.005 * sampleRate);  // default: 5 ms
+  private vadCloseRampRate = 1.0 / (0.02 * sampleRate);  // default: 20 ms
 
   // TEN-VAD state
   private vadEnabled = false;
@@ -275,6 +276,7 @@ class NoiseGateProcessor extends AudioWorkletProcessor {
       vadEnabled: false,
       vadPositiveThreshold: 0.5,
       vadNegativeThreshold: 0.3,
+      vadAggressive: false,
     });
 
     this.port.postMessage({
@@ -295,6 +297,13 @@ class NoiseGateProcessor extends AudioWorkletProcessor {
     this.vadEnabled = p.vadEnabled ?? false;
     this.vadPositiveThreshold = p.vadPositiveThreshold ?? 0.5;
     this.vadNegativeThreshold = p.vadNegativeThreshold ?? 0.3;
+    if (p.vadAggressive) {
+      this.vadOpenRampRate  = 1.0 / (0.001 * sampleRate); // 1 ms — near-instant
+      this.vadCloseRampRate = 1.0 / (0.005 * sampleRate); // 5 ms
+    } else {
+      this.vadOpenRampRate  = 1.0 / (0.005 * sampleRate); // 5 ms
+      this.vadCloseRampRate = 1.0 / (0.02  * sampleRate); // 20 ms
+    }
     // When VAD is disabled, open the gate immediately
     if (!this.vadEnabled) this.vadGateOpen = true;
     this.port.postMessage({

src/livekit/NoiseGateTransformer.ts

@@ -23,6 +23,7 @@ export interface NoiseGateParams {
   vadEnabled: boolean;
   vadPositiveThreshold: number; // open gate when isSpeech prob >= this (0–1)
   vadNegativeThreshold: number; // close gate when isSpeech prob < this (0–1)
+  vadAggressive: boolean;       // true: 1 ms open / 5 ms close ramp; false: 5 ms / 20 ms
 }
 
 /**

src/settings/SettingsModal.tsx

@@ -35,6 +35,7 @@ import {
   vadEnabled as vadEnabledSetting,
   vadPositiveThreshold as vadPositiveThresholdSetting,
   vadNegativeThreshold as vadNegativeThresholdSetting,
+  vadMode as vadModeSetting,
 } from "./settings";
 import { PreferencesSettingsTab } from "./PreferencesSettingsTab";
 import { Slider } from "../Slider";
@@ -134,6 +135,7 @@ export const SettingsModal: FC<Props> = ({
 
   // Voice activity detection
   const [vadActive, setVadActive] = useSetting(vadEnabledSetting);
+  const [vadModeValue, setVadModeValue] = useSetting(vadModeSetting);
   const [vadPositiveThreshold, setVadPositiveThreshold] = useSetting(vadPositiveThresholdSetting);
   const [vadPositiveThresholdRaw, setVadPositiveThresholdRaw] = useState(vadPositiveThreshold);
   const [vadNegativeThreshold, setVadNegativeThreshold] = useSetting(vadNegativeThresholdSetting);
@@ -336,7 +338,7 @@ export const SettingsModal: FC<Props> = ({
               id="vadEnabled"
               type="checkbox"
               label="Enable voice activity detection"
-              description="Uses TEN-VAD to mute audio when no speech is detected (~16 ms latency)."
+              description="Uses TEN-VAD to mute audio when no speech is detected (~10 ms latency)."
               checked={vadActive}
               onChange={(e: ChangeEvent<HTMLInputElement>): void =>
                 setVadActive(e.target.checked)
@@ -345,6 +347,28 @@ export const SettingsModal: FC<Props> = ({
           </FieldRow>
           {vadActive && (
             <>
+              <FieldRow>
+                <InputField
+                  id="vadModeStandard"
+                  type="radio"
+                  name="vadMode"
+                  label="Standard"
+                  description="5 ms open / 20 ms close ramp — comfortable feel."
+                  checked={vadModeValue === "standard"}
+                  onChange={(): void => setVadModeValue("standard")}
+                />
+              </FieldRow>
+              <FieldRow>
+                <InputField
+                  id="vadModeAggressive"
+                  type="radio"
+                  name="vadMode"
+                  label="Aggressive"
+                  description="1 ms open / 5 ms close ramp — lowest possible latency."
+                  checked={vadModeValue === "aggressive"}
+                  onChange={(): void => setVadModeValue("aggressive")}
+                />
+              </FieldRow>
               <div className={`${styles.volumeSlider} ${styles.thresholdSlider}`}>
                 <span className={styles.sliderLabel}>Open threshold: {Math.round(vadPositiveThresholdRaw * 100)}%</span>
                 <p>How confident the model must be before opening the gate.</p>

src/settings/settings.ts

@@ -150,6 +150,8 @@ export const vadEnabled = new Setting<boolean>("vad-enabled", false);
 export const vadPositiveThreshold = new Setting<number>("vad-positive-threshold", 0.2);
 // Probability below which the VAD closes the gate (0–1)
 export const vadNegativeThreshold = new Setting<number>("vad-negative-threshold", 0.1);
+// standard: 5 ms open / 20 ms close ramp  aggressive: 1 ms open / 5 ms close ramp
+export const vadMode = new Setting<"standard" | "aggressive">("vad-mode", "standard");
 
 export const transientSuppressorEnabled = new Setting<boolean>(
   "transient-suppressor-enabled",

src/state/CallViewModel/localMember/Publisher.ts

@@ -44,6 +44,7 @@ import {
   vadEnabled,
   vadPositiveThreshold,
   vadNegativeThreshold,
+  vadMode,
 } from "../../../settings/settings.ts";
 import {
   type NoiseGateParams,
@@ -451,6 +452,7 @@ export class Publisher {
       vadEnabled: vadEnabled.getValue(),
       vadPositiveThreshold: vadPositiveThreshold.getValue(),
       vadNegativeThreshold: vadNegativeThreshold.getValue(),
+      vadAggressive: vadMode.getValue() === "aggressive",
     });
 
     // Attach / detach processor when any processing feature changes or the track changes.
@@ -509,12 +511,13 @@ export class Publisher {
       vadEnabled.value$,
       vadPositiveThreshold.value$,
       vadNegativeThreshold.value$,
+      vadMode.value$,
     ])
       .pipe(scope.bind())
       .subscribe(([
         noiseGateActive, threshold, attackMs, holdMs, releaseMs,
         transientEnabled, transientThresholdDb, transientReleaseMs,
-        vadActive, vadPos, vadNeg,
+        vadActive, vadPos, vadNeg, vadModeValue,
       ]) => {
         transformer?.updateParams({
           noiseGateActive, threshold, attackMs, holdMs, releaseMs,
@@ -522,6 +525,7 @@ export class Publisher {
           vadEnabled: vadActive,
           vadPositiveThreshold: vadPos,
           vadNegativeThreshold: vadNeg,
+          vadAggressive: vadModeValue === "aggressive",
         });
       });
   }