feat: add restore defaults button to transient suppressor

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

src/livekit/NoiseGateProcessor.worklet.ts

@@ -25,6 +25,9 @@ interface NoiseGateParams {
   attackMs: number;
   holdMs: number;
   releaseMs: number;
+  transientEnabled: boolean;
+  transientThresholdDb: number; // dB above background RMS that triggers suppression
+  transientReleaseMs: number;   // how quickly suppression fades after transient ends
 }
 
 function dbToLinear(db: number): number {
@@ -32,21 +35,36 @@ function dbToLinear(db: number): number {
 }
 
 /**
- * AudioWorkletProcessor implementing a noise gate.
+ * AudioWorkletProcessor implementing a noise gate and an optional transient
+ * suppressor, both running per-sample in a single pass.
  *
- * Per-sample peak detection across all channels. Gate opens when the
- * instantaneous peak exceeds the threshold and closes when it drops below.
+ * Noise gate: opens when instantaneous peak exceeds threshold, closes below.
  * Attack, hold, and release times smooth the attenuation envelope.
+ *
+ * Transient suppressor: tracks a slow-moving RMS background level. When the
+ * instantaneous peak exceeds the background by more than transientThresholdDb,
+ * gain is instantly cut to 0 and releases over transientReleaseMs. This catches
+ * desk hits, mic bumps, and other sudden loud impacts without affecting speech.
  */
 class NoiseGateProcessor extends AudioWorkletProcessor {
+  // Noise gate state
   private threshold = dbToLinear(-60);
-  private attackRate = 1.0 / (0.025 * 48000);
-  private releaseRate = 1.0 / (0.15 * 48000);
+  private attackRate = 1.0 / (0.025 * sampleRate);
+  private releaseRate = 1.0 / (0.15 * sampleRate);
   private holdTime = 0.2;
-
   private isOpen = false;
-  private attenuation = 0;
+  private gateAttenuation = 0;
   private heldTime = 0;
+
+  // Transient suppressor state
+  private transientEnabled = false;
+  private transientRatio = dbToLinear(15); // peak must exceed rms by this factor
+  private transientReleaseRate = 1.0 / (0.08 * sampleRate);
+  private transientAttenuation = 1.0;  // 1 = fully open, ramps to 0 on transient
+  private slowRms = 0;
+  // Exponential smoothing coefficient for background RMS (~200ms time constant)
+  private rmsCoeff = Math.exp(-1.0 / (0.2 * sampleRate));
+
   private logCounter = 0;
 
   public constructor() {
@@ -54,7 +72,10 @@ class NoiseGateProcessor extends AudioWorkletProcessor {
     this.port.onmessage = (e: MessageEvent<NoiseGateParams>): void => {
       this.updateParams(e.data);
     };
-    this.updateParams({ threshold: -60, attackMs: 25, holdMs: 200, releaseMs: 150 });
+    this.updateParams({
+      threshold: -60, attackMs: 25, holdMs: 200, releaseMs: 150,
+      transientEnabled: false, transientThresholdDb: 15, transientReleaseMs: 80,
+    });
     this.port.postMessage({ type: "log", msg: "[NoiseGate worklet] constructor called, sampleRate=" + sampleRate });
   }
 
@@ -63,12 +84,14 @@ class NoiseGateProcessor extends AudioWorkletProcessor {
     this.attackRate = 1.0 / ((p.attackMs / 1000) * sampleRate);
     this.releaseRate = 1.0 / ((p.releaseMs / 1000) * sampleRate);
     this.holdTime = p.holdMs / 1000;
+    this.transientEnabled = p.transientEnabled;
+    this.transientRatio = dbToLinear(p.transientThresholdDb);
+    this.transientReleaseRate = 1.0 / ((p.transientReleaseMs / 1000) * sampleRate);
     this.port.postMessage({
       type: "log",
-      msg: "[NoiseGate worklet] params: threshold=" + this.threshold.toFixed(5)
-        + " attack=" + this.attackRate.toFixed(8)
-        + " release=" + this.releaseRate.toFixed(8)
-        + " hold=" + this.holdTime,
+      msg: "[NoiseGate worklet] params updated: threshold=" + p.threshold
+        + " transientEnabled=" + p.transientEnabled
+        + " transientThresholdDb=" + p.transientThresholdDb,
     });
   }
 
@@ -79,7 +102,7 @@ class NoiseGateProcessor extends AudioWorkletProcessor {
 
     const channels = input.length;
     const blockSize = input[0]?.length ?? 128;
-    const sampleRateI = 1.0 / sampleRate;
+    const samplePeriod = 1.0 / sampleRate;
 
     for (let i = 0; i < blockSize; i++) {
       // Peak detection across all channels
@@ -88,32 +111,50 @@ class NoiseGateProcessor extends AudioWorkletProcessor {
         curLevel = Math.max(curLevel, Math.abs(input[j]?.[i] ?? 0));
       }
 
-      // Open gate when signal exceeds threshold
+      // --- Transient suppressor ---
+      let transientGain = 1.0;
+      if (this.transientEnabled) {
+        // Update slow RMS background (exponential moving average of energy)
+        this.slowRms = Math.sqrt(
+          this.rmsCoeff * this.slowRms * this.slowRms +
+          (1.0 - this.rmsCoeff) * curLevel * curLevel,
+        );
+
+        const background = Math.max(this.slowRms, 1e-6);
+        if (curLevel > background * this.transientRatio) {
+          // Transient detected — instantly cut gain
+          this.transientAttenuation = 0.0;
+        } else {
+          // Release: ramp back toward 1
+          this.transientAttenuation = Math.min(1.0, this.transientAttenuation + this.transientReleaseRate);
+        }
+        transientGain = this.transientAttenuation;
+      }
+
+      // --- Noise gate ---
       if (curLevel > this.threshold && !this.isOpen) {
         this.isOpen = true;
       }
-
-      // Close gate when signal drops below threshold; hold timer starts
       if (curLevel <= this.threshold && this.isOpen) {
         this.heldTime = 0;
         this.isOpen = false;
       }
-
-      // Ramp attenuation toward 1 (open) or wait for hold then ramp toward 0 (closed)
       if (this.isOpen) {
-        this.attenuation = Math.min(1.0, this.attenuation + this.attackRate);
+        this.gateAttenuation = Math.min(1.0, this.gateAttenuation + this.attackRate);
       } else {
-        this.heldTime += sampleRateI;
+        this.heldTime += samplePeriod;
         if (this.heldTime > this.holdTime) {
-          this.attenuation = Math.max(0.0, this.attenuation - this.releaseRate);
+          this.gateAttenuation = Math.max(0.0, this.gateAttenuation - this.releaseRate);
         }
       }
 
+      const gain = this.gateAttenuation * transientGain;
+
       for (let c = 0; c < output.length; c++) {
         const inCh = input[c] ?? input[0];
         const outCh = output[c];
         if (inCh && outCh) {
-          outCh[i] = (inCh[i] ?? 0) * this.attenuation;
+          outCh[i] = (inCh[i] ?? 0) * gain;
         }
       }
     }
@@ -122,9 +163,10 @@ class NoiseGateProcessor extends AudioWorkletProcessor {
     if (this.logCounter % 375 === 0) {
       this.port.postMessage({
         type: "log",
-        msg: "[NoiseGate worklet] isOpen=" + this.isOpen
-          + " attenuation=" + this.attenuation.toFixed(3)
-          + " heldTime=" + this.heldTime.toFixed(3),
+        msg: "[NoiseGate worklet] gateOpen=" + this.isOpen
+          + " gateAtten=" + this.gateAttenuation.toFixed(3)
+          + " transientAtten=" + this.transientAttenuation.toFixed(3)
+          + " slowRms=" + this.slowRms.toFixed(5),
       });
     }
 

src/livekit/NoiseGateTransformer.ts

@@ -15,6 +15,9 @@ export interface NoiseGateParams {
   attackMs: number;
   holdMs: number;
   releaseMs: number;
+  transientEnabled: boolean;
+  transientThresholdDb: number; // dB above background RMS that triggers suppression
+  transientReleaseMs: number;   // ms for suppression to fade after transient ends
 }
 
 /**

src/settings/SettingsModal.tsx

@@ -29,6 +29,9 @@ import {
   noiseGateAttack as noiseGateAttackSetting,
   noiseGateHold as noiseGateHoldSetting,
   noiseGateRelease as noiseGateReleaseSetting,
+  transientSuppressorEnabled as transientSuppressorEnabledSetting,
+  transientThreshold as transientThresholdSetting,
+  transientRelease as transientReleaseSetting,
 } from "./settings";
 import { PreferencesSettingsTab } from "./PreferencesSettingsTab";
 import { Slider } from "../Slider";
@@ -126,6 +129,20 @@ export const SettingsModal: FC<Props> = ({
 
   const [showAdvancedGate, setShowAdvancedGate] = useState(false);
 
+  // Transient suppressor settings
+  const [transientEnabled, setTransientEnabled] = useSetting(transientSuppressorEnabledSetting);
+  const [transientThreshold, setTransientThreshold] = useSetting(transientThresholdSetting);
+  const [transientThresholdRaw, setTransientThresholdRaw] = useState(transientThreshold);
+  const [transientRelease, setTransientRelease] = useSetting(transientReleaseSetting);
+  const [transientReleaseRaw, setTransientReleaseRaw] = useState(transientRelease);
+
+  const resetTransientDefaults = useCallback((): void => {
+    const t = transientThresholdSetting.defaultValue;
+    const r = transientReleaseSetting.defaultValue;
+    setTransientThreshold(t); setTransientThresholdRaw(t);
+    setTransientRelease(r);   setTransientReleaseRaw(r);
+  }, [setTransientThreshold, setTransientRelease]);
+
   const resetGateDefaults = useCallback((): void => {
     const a = noiseGateAttackSetting.defaultValue;
     const h = noiseGateHoldSetting.defaultValue;
@@ -293,6 +310,67 @@ export const SettingsModal: FC<Props> = ({
           </>
         )}
         </div>
+        <div className={styles.noiseGateSection}>
+          <Heading
+            type="body"
+            weight="semibold"
+            size="sm"
+            as="h4"
+            className={styles.noiseGateHeading}
+          >
+            Transient Suppressor
+          </Heading>
+          <Separator className={styles.noiseGateSeparator} />
+          <FieldRow>
+            <InputField
+              id="transientEnabled"
+              type="checkbox"
+              label="Enable transient suppressor"
+              description="Cut sudden loud impacts like desk hits or mic bumps."
+              checked={transientEnabled}
+              onChange={(e: ChangeEvent<HTMLInputElement>): void =>
+                setTransientEnabled(e.target.checked)
+              }
+            />
+          </FieldRow>
+          {transientEnabled && (
+            <>
+              <div className={`${styles.volumeSlider} ${styles.thresholdSlider}`}>
+                <span className={styles.sliderLabel}>Sensitivity: {transientThresholdRaw} dB above background</span>
+                <p>Lower values catch more impacts; higher values only catch the loudest ones.</p>
+                <Slider
+                  label="Transient threshold"
+                  value={transientThresholdRaw}
+                  onValueChange={setTransientThresholdRaw}
+                  onValueCommit={setTransientThreshold}
+                  min={8}
+                  max={30}
+                  step={1}
+                  tooltip={false}
+                />
+              </div>
+              <div className={styles.volumeSlider}>
+                <span className={styles.sliderLabel}>Release: {transientReleaseRaw} ms</span>
+                <p>How quickly audio returns after suppression.</p>
+                <Slider
+                  label="Transient release"
+                  value={transientReleaseRaw}
+                  onValueChange={setTransientReleaseRaw}
+                  onValueCommit={setTransientRelease}
+                  min={20}
+                  max={200}
+                  step={10}
+                  tooltip={false}
+                />
+              </div>
+              <div className={styles.restoreDefaults}>
+                <Button kind="secondary" size="sm" onClick={resetTransientDefaults}>
+                  Restore defaults
+                </Button>
+              </div>
+            </>
+          )}
+        </div>
       </>
     ),
   };

src/settings/settings.ts

@@ -145,6 +145,21 @@ export const noiseGateHold = new Setting<number>("noise-gate-hold", 200);
 // Time in ms for the gate to fully close after hold expires
 export const noiseGateRelease = new Setting<number>("noise-gate-release", 150);
 
+export const transientSuppressorEnabled = new Setting<boolean>(
+  "transient-suppressor-enabled",
+  false,
+);
+// How many dB above the background RMS a peak must be to trigger suppression
+export const transientThreshold = new Setting<number>(
+  "transient-suppressor-threshold",
+  15,
+);
+// Time in ms for suppression to fade after transient ends
+export const transientRelease = new Setting<number>(
+  "transient-suppressor-release",
+  80,
+);
+
 export enum MatrixRTCMode {
   Legacy = "legacy",
   Compatibility = "compatibility",

src/state/CallViewModel/localMember/Publisher.ts

@@ -38,6 +38,9 @@ import {
   noiseGateAttack,
   noiseGateHold,
   noiseGateRelease,
+  transientSuppressorEnabled,
+  transientThreshold,
+  transientRelease,
 } from "../../../settings/settings.ts";
 import {
   type NoiseGateParams,
@@ -438,6 +441,9 @@ export class Publisher {
       attackMs: noiseGateAttack.getValue(),
       holdMs: noiseGateHold.getValue(),
       releaseMs: noiseGateRelease.getValue(),
+      transientEnabled: transientSuppressorEnabled.getValue(),
+      transientThresholdDb: transientThreshold.getValue(),
+      transientReleaseMs: transientRelease.getValue(),
     });
 
     // Attach / detach processor when enabled state or the track changes.
@@ -482,10 +488,17 @@ export class Publisher {
       noiseGateAttack.value$,
       noiseGateHold.value$,
       noiseGateRelease.value$,
+      transientSuppressorEnabled.value$,
+      transientThreshold.value$,
+      transientRelease.value$,
     ])
       .pipe(scope.bind())
-      .subscribe(([threshold, attackMs, holdMs, releaseMs]) => {
-        transformer?.updateParams({ threshold, attackMs, holdMs, releaseMs });
+      .subscribe(([threshold, attackMs, holdMs, releaseMs,
+                   transientEnabled, transientThresholdDb, transientReleaseMs]) => {
+        transformer?.updateParams({
+          threshold, attackMs, holdMs, releaseMs,
+          transientEnabled, transientThresholdDb, transientReleaseMs,
+        });
       });
   }