From a4995606e5b79dc0eb3ae3af1a6ef7a32b0e1d0c Mon Sep 17 00:00:00 2001
From: Bryan Van Deusen <bryan.vandeusen@fabledsword.com>
Date: Thu, 16 Apr 2026 17:47:45 -0400
Subject: [PATCH] chore(voice): remove amplitude-based silence detector
 (replaced by VAD)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 .../src/composables/useSilenceDetector.ts     | 121 ------------------
 1 file changed, 121 deletions(-)
 delete mode 100644 frontend/src/composables/useSilenceDetector.ts

diff --git a/frontend/src/composables/useSilenceDetector.ts b/frontend/src/composables/useSilenceDetector.ts
deleted file mode 100644
index db5c29a..0000000
--- a/frontend/src/composables/useSilenceDetector.ts
+++ /dev/null
@@ -1,121 +0,0 @@
-import { ref, readonly } from 'vue'
-
-export interface SilenceDetectorOptions {
-  /**
-   * Absolute fallback silence threshold in dBFS, used during the first
-   * moments before any real speech has been observed. Once the session peak
-   * clears `dynamicArmDb` we switch to the dynamic threshold instead.
-   */
-  fallbackThresholdDb?: number // default -45
-  /** How many dB below the session peak counts as "silent" once armed. */
-  dropFromPeakDb?: number // default 15
-  /**
-   * Session peak must reach this level (dBFS) before dynamic thresholding
-   * kicks in. Until then the fallback threshold is used so we don't lock
-   * onto a noise-floor peak.
-   */
-  dynamicArmDb?: number // default -25
-  /** How long to wait at the start of recording before running silence checks. */
-  graceMs?: number // default 1500
-  silenceDurationMs?: number // default 2000
-  minRecordingMs?: number // default 500
-}
-
-/**
- * Mic silence detector + live amplitude signal.
- *
- * Uses `getFloatTimeDomainData()` for honest linear RMS in [-1, 1] space,
- * then derives dBFS for the silence threshold. The previous implementation
- * ran RMS over `getByteFrequencyData` bytes — those bytes are already a
- * dB-scaled quantity, so taking their RMS and re-log'ing it produced
- * numbers that didn't line up with real dBFS and made any static threshold
- * unpredictable.
- *
- * Silence threshold is dynamic: we track the session peak dBFS and treat
- * "silent" as "current level is at least [dropFromPeakDb] below peak."
- * This auto-calibrates to whatever mic and room the user is on. Until the
- * peak climbs above [dynamicArmDb] we fall back to a conservative static
- * threshold so a quiet room doesn't spin forever. A grace period at the
- * start of the recording gives the user time to begin speaking before
- * silence checks arm.
- *
- * `amplitude` is the raw linear RMS scaled ×5 and clamped to 1 so quiet
- * speech still visibly moves UI that binds to it.
- */
-export function useSilenceDetector(options: SilenceDetectorOptions = {}) {
-  const {
-    fallbackThresholdDb = -45,
-    dropFromPeakDb = 15,
-    dynamicArmDb = -25,
-    graceMs = 1500,
-    silenceDurationMs = 2000,
-    minRecordingMs = 500,
-  } = options
-
-  const amplitude = ref(0)
-  let audioCtx: AudioContext | null = null
-  let intervalId: ReturnType<typeof setInterval> | null = null
-  let silenceMs = 0
-  let startedAt = 0
-  let peakDb = -100
-
-  function start(stream: MediaStream, onSilence: () => void): void {
-    stop()
-    audioCtx = new AudioContext()
-    // Some browsers start AudioContext in "suspended" state — resume so
-    // the analyser returns real values instead of all zeros.
-    audioCtx.resume().catch(() => {})
-    const source = audioCtx.createMediaStreamSource(stream)
-    const analyser = audioCtx.createAnalyser()
-    analyser.fftSize = 1024
-    source.connect(analyser)
-
-    const samples = new Float32Array(analyser.fftSize)
-    silenceMs = 0
-    startedAt = Date.now()
-    peakDb = -100
-
-    intervalId = setInterval(() => {
-      analyser.getFloatTimeDomainData(samples)
-      let sumSq = 0
-      for (let i = 0; i < samples.length; i++) sumSq += samples[i] * samples[i]
-      const rms = Math.sqrt(sumSq / samples.length)
-      amplitude.value = Math.min(rms * 5, 1)
-
-      const db = rms > 1e-7 ? 20 * Math.log10(rms) : -100
-      if (db > peakDb) peakDb = db
-
-      const elapsed = Date.now() - startedAt
-      if (elapsed < graceMs) return
-
-      const threshold =
-        peakDb > dynamicArmDb ? peakDb - dropFromPeakDb : fallbackThresholdDb
-
-      if (db < threshold) {
-        silenceMs += 100
-        if (silenceMs >= silenceDurationMs && elapsed >= minRecordingMs) {
-          stop()
-          onSilence()
-        }
-      } else {
-        silenceMs = 0
-      }
-    }, 100)
-  }
-
-  function stop(): void {
-    if (intervalId !== null) {
-      clearInterval(intervalId)
-      intervalId = null
-    }
-    if (audioCtx) {
-      audioCtx.close().catch(() => {})
-      audioCtx = null
-    }
-    amplitude.value = 0
-    silenceMs = 0
-    peakDb = -100
-  }
-
-  return { amplitude: readonly(amplitude), start, stop }
-}