diff --git a/src/helpers/whisperVadConfig.js b/src/helpers/whisperVadConfig.js
index 8cbc72901..fab62c4bc 100644
--- a/src/helpers/whisperVadConfig.js
+++ b/src/helpers/whisperVadConfig.js
@@ -6,8 +6,10 @@ const VAD_LIMITS = Object.freeze(LIMITS);
 function clampVadField(key, value) {
   const fallback = DEFAULTS[key];
   const n = value === null || value === undefined || value === "" ? fallback : Number(value);
-  if (!Number.isFinite(n)) return fallback;
-  const { min, max, round } = LIMITS[key];
+  if (!Number.isFinite(n)) return fallback !== undefined ? fallback : value;
+  const limit = LIMITS[key];
+  if (!limit) return n;
+  const { min, max, round } = limit;
   const clamped = Math.min(max, Math.max(min, n));
   return round ? Math.round(clamped) : clamped;
 }
@@ -26,9 +28,14 @@ function resolveContextSileroEnabled(settings = {}, context = "dictation") {
   // leave Whisper decoding near-silence seeded with the dictionary prompt, which
   // replaces the transcript with dictionary words (#1454). Long-form contexts
   // (notes, meetings) keep VAD to skip extended silence.
-  if (context === "dictation") return settings?.dictationSileroEnabled === true;
-  if (context === "noteRecording") return settings?.noteRecordingSileroEnabled !== false;
-  if (context === "meeting") return settings?.meetingSileroEnabled !== false;
+  const normalizedContext =
+    typeof context === "string" ? context.trim().toLowerCase() : "dictation";
+
+  if (normalizedContext === "dictation") return settings?.dictationSileroEnabled === true;
+  if (normalizedContext === "noterecording" || normalizedContext === "note_recording") {
+    return settings?.noteRecordingSileroEnabled !== false;
+  }
+  if (normalizedContext === "meeting") return settings?.meetingSileroEnabled !== false;
   return true;
 }
 
diff --git a/test/helpers/whisperVadConfig.test.js b/test/helpers/whisperVadConfig.test.js
index f3fa5f225..9b7164935 100644
--- a/test/helpers/whisperVadConfig.test.js
+++ b/test/helpers/whisperVadConfig.test.js
@@ -47,3 +47,20 @@ test("resolveContextSileroEnabled defaults dictation off, other contexts on", as
   assert.equal(resolveContextSileroEnabled({}, "noteRecording"), true);
   assert.equal(resolveContextSileroEnabled({}, "meeting"), true);
 });
+
+test("clampVadField handles unknown keys safely without throwing", async () => {
+  const { clampVadField } = await import("../../src/helpers/whisperVadConfig.js");
+  assert.equal(clampVadField("unknownField", 42), 42);
+  assert.equal(clampVadField(null, 42), 42);
+});
+
+test("resolveContextSileroEnabled normalizes casing and whitespace in context", async () => {
+  const { resolveContextSileroEnabled } = await import("../../src/helpers/whisperVadConfig.js");
+  assert.equal(resolveContextSileroEnabled({}, " DICTATION "), false);
+  assert.equal(resolveContextSileroEnabled({}, "NoteRecording"), true);
+  assert.equal(resolveContextSileroEnabled({}, " MEETING "), true);
+  assert.equal(
+    resolveContextSileroEnabled({ dictationSileroEnabled: true }, "Dictation"),
+    true
+  );
+});