diff --git a/src/App.tsx b/src/App.tsx
index 5e50e3a..191e751 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -4,6 +4,7 @@ import FileViewer from "./components/FileViewer";
 import UpdateNotifier from "./components/UpdateNotifier";
 import WelcomeScreen from "./components/WelcomeScreen";
 import { useFileSession } from "./hooks/useFileSession";
+import type { FileAction } from "./types";
 import "./electron.d.ts";
 
 type AppState = "welcome" | "viewing" | "completed";
@@ -38,7 +39,7 @@ function App() {
     }
   };
 
-  const handleFileAction = async (action: "delete" | "keep") => {
+  const handleFileAction = async (action: FileAction) => {
     if (action === "delete") {
       await deleteFile();
     } else {
diff --git a/src/components/FileViewer.tsx b/src/components/FileViewer.tsx
index f18d38f..6cc384a 100644
--- a/src/components/FileViewer.tsx
+++ b/src/components/FileViewer.tsx
@@ -1,13 +1,20 @@
 import { ArrowLeft, CheckCircle, Eye, RotateCcw, Settings, XCircle } from "lucide-react";
 import type React from "react";
 import { useCallback, useEffect, useState } from "react";
-import { type AppSettings, formatDate, formatFileSize, type SessionState } from "../types";
+import { playActionSound } from "../sound";
+import {
+  type AppSettings,
+  type FileAction,
+  formatDate,
+  formatFileSize,
+  type SessionState,
+} from "../types";
 import FilePreview from "./FilePreview";
 import SettingsComponent from "./Settings";
 
 interface FileViewerProps {
   sessionState: SessionState;
-  onFileAction: (action: "delete" | "keep") => Promise<void>;
+  onFileAction: (action: FileAction) => Promise<void>;
   onUndo: () => void;
   onBack: () => void;
 }
@@ -25,7 +32,7 @@ const FileViewer: React.FC<FileViewerProps> = ({ sessionState, onFileAction, onU
   });
   const [actionFeedback, setActionFeedback] = useState<{
     show: boolean;
-    type: "delete" | "keep";
+    type: FileAction;
   }>({ show: false, type: "delete" });
 
   // Load settings on component mount
@@ -50,115 +57,8 @@ const FileViewer: React.FC<FileViewerProps> = ({ sessionState, onFileAction, onU
     }
   }, []);
 
-  const playActionSound = useCallback(
-    (action: "delete" | "keep") => {
-      if (!settings.soundEffects) return;
-
-      // Create audio context for sound feedback
-      try {
-        const audioContext = new (
-          window.AudioContext ||
-          (window as unknown as { webkitAudioContext: typeof AudioContext }).webkitAudioContext
-        )();
-
-        if (action === "delete") {
-          // Delete sound: Descending "whoosh" effect (like something being thrown away)
-          const oscillator1 = audioContext.createOscillator();
-          const oscillator2 = audioContext.createOscillator();
-          const gainNode = audioContext.createGain();
-          const filter = audioContext.createBiquadFilter();
-
-          // Connect: oscillators -> filter -> gain -> destination
-          oscillator1.connect(filter);
-          oscillator2.connect(filter);
-          filter.connect(gainNode);
-          gainNode.connect(audioContext.destination);
-
-          // Two oscillators for richer sound
-          oscillator1.frequency.setValueAtTime(300, audioContext.currentTime);
-          oscillator1.frequency.exponentialRampToValueAtTime(50, audioContext.currentTime + 0.3);
-          oscillator1.type = "sawtooth";
-
-          oscillator2.frequency.setValueAtTime(200, audioContext.currentTime);
-          oscillator2.frequency.exponentialRampToValueAtTime(30, audioContext.currentTime + 0.3);
-          oscillator2.type = "triangle";
-
-          // Low-pass filter for "whoosh" effect
-          filter.type = "lowpass";
-          filter.frequency.setValueAtTime(800, audioContext.currentTime);
-          filter.frequency.exponentialRampToValueAtTime(200, audioContext.currentTime + 0.3);
-
-          // Volume envelope
-          gainNode.gain.setValueAtTime(0.15, audioContext.currentTime);
-          gainNode.gain.exponentialRampToValueAtTime(0.01, audioContext.currentTime + 0.3);
-
-          oscillator1.start(audioContext.currentTime);
-          oscillator1.stop(audioContext.currentTime + 0.3);
-          oscillator2.start(audioContext.currentTime);
-          oscillator2.stop(audioContext.currentTime + 0.3);
-        } else {
-          // Keep sound: Ascending "chime" effect (like a positive confirmation)
-          const oscillator1 = audioContext.createOscillator();
-          const oscillator2 = audioContext.createOscillator();
-          const oscillator3 = audioContext.createOscillator();
-          const gainNode = audioContext.createGain();
-          const filter = audioContext.createBiquadFilter();
-
-          // Connect: oscillators -> filter -> gain -> destination
-          oscillator1.connect(filter);
-          oscillator2.connect(filter);
-          oscillator3.connect(filter);
-          filter.connect(gainNode);
-          gainNode.connect(audioContext.destination);
-
-          // Three oscillators for a pleasant chord
-          oscillator1.frequency.setValueAtTime(523.25, audioContext.currentTime); // C5
-          oscillator1.frequency.exponentialRampToValueAtTime(
-            659.25,
-            audioContext.currentTime + 0.2
-          ); // E5
-          oscillator1.type = "sine";
-
-          oscillator2.frequency.setValueAtTime(659.25, audioContext.currentTime); // E5
-          oscillator2.frequency.exponentialRampToValueAtTime(
-            783.99,
-            audioContext.currentTime + 0.2
-          ); // G5
-          oscillator2.type = "sine";
-
-          oscillator3.frequency.setValueAtTime(783.99, audioContext.currentTime); // G5
-          oscillator3.frequency.exponentialRampToValueAtTime(
-            1046.5,
-            audioContext.currentTime + 0.2
-          ); // C6
-          oscillator3.type = "sine";
-
-          // High-pass filter for bright, clear sound
-          filter.type = "highpass";
-          filter.frequency.setValueAtTime(400, audioContext.currentTime);
-
-          // Volume envelope with quick attack and decay
-          gainNode.gain.setValueAtTime(0, audioContext.currentTime);
-          gainNode.gain.linearRampToValueAtTime(0.12, audioContext.currentTime + 0.05);
-          gainNode.gain.exponentialRampToValueAtTime(0.01, audioContext.currentTime + 0.25);
-
-          oscillator1.start(audioContext.currentTime);
-          oscillator1.stop(audioContext.currentTime + 0.25);
-          oscillator2.start(audioContext.currentTime);
-          oscillator2.stop(audioContext.currentTime + 0.25);
-          oscillator3.start(audioContext.currentTime);
-          oscillator3.stop(audioContext.currentTime + 0.25);
-        }
-      } catch (_error) {
-        // Silently fail if audio context is not available
-        console.log("Audio feedback not available");
-      }
-    },
-    [settings.soundEffects]
-  );
-
   const performAction = useCallback(
-    async (action: "delete" | "keep") => {
+    async (action: FileAction) => {
       // Check if we need confirmation for delete
       if (action === "delete" && settings.confirmDelete) {
         const confirmed = window.confirm(`Are you sure you want to delete "${currentFile.name}"?`);
@@ -169,7 +69,9 @@ const FileViewer: React.FC<FileViewerProps> = ({ sessionState, onFileAction, onU
       setActionFeedback({ show: true, type: action });
 
       // Play audio feedback
-      playActionSound(action);
+      if (settings.soundEffects) {
+        playActionSound(action);
+      }
 
       // Trigger action after brief delay for feedback
       setTimeout(async () => {
@@ -184,7 +86,7 @@ const FileViewer: React.FC<FileViewerProps> = ({ sessionState, onFileAction, onU
         setActionFeedback({ show: false, type: action });
       }, 200);
     },
-    [onFileAction, playActionSound, settings.confirmDelete, currentFile.name]
+    [onFileAction, settings.confirmDelete, settings.soundEffects, currentFile.name]
   );
 
   // Keyboard shortcuts
diff --git a/src/sound.test.ts b/src/sound.test.ts
new file mode 100644
index 0000000..4f3de0b
--- /dev/null
+++ b/src/sound.test.ts
@@ -0,0 +1,78 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+// A fake AudioContext: enough of the graph (oscillator/gain/filter nodes,
+// their scheduling methods) for sound.ts to run without throwing, so tests
+// can assert on construction rather than on exact frequencies/envelopes.
+function mockAudioContext() {
+  const node = () => ({
+    connect: vi.fn(),
+    frequency: { setValueAtTime: vi.fn(), exponentialRampToValueAtTime: vi.fn() },
+    gain: {
+      setValueAtTime: vi.fn(),
+      exponentialRampToValueAtTime: vi.fn(),
+      linearRampToValueAtTime: vi.fn(),
+    },
+    type: "",
+    start: vi.fn(),
+    stop: vi.fn(),
+  });
+
+  return vi.fn(() => ({
+    currentTime: 0,
+    destination: {},
+    createOscillator: vi.fn(node),
+    createGain: vi.fn(node),
+    createBiquadFilter: vi.fn(node),
+  }));
+}
+
+describe("playActionSound", () => {
+  beforeEach(() => {
+    // sound.ts caches its AudioContext in module state, so each test needs a
+    // fresh module instance to observe construction in isolation.
+    vi.resetModules();
+  });
+
+  afterEach(() => {
+    // @ts-expect-error test-only cleanup of a global this suite sets up
+    window.AudioContext = undefined;
+  });
+
+  it("does not throw when AudioContext is unavailable", async () => {
+    const { playActionSound } = await import("./sound");
+
+    expect(() => playActionSound("delete")).not.toThrow();
+    expect(() => playActionSound("keep")).not.toThrow();
+  });
+
+  it("constructs an AudioContext to play a delete sound", async () => {
+    const ctor = mockAudioContext();
+    window.AudioContext = ctor as unknown as typeof AudioContext;
+    const { playActionSound } = await import("./sound");
+
+    playActionSound("delete");
+
+    expect(ctor).toHaveBeenCalledOnce();
+  });
+
+  it("constructs an AudioContext to play a keep sound", async () => {
+    const ctor = mockAudioContext();
+    window.AudioContext = ctor as unknown as typeof AudioContext;
+    const { playActionSound } = await import("./sound");
+
+    playActionSound("keep");
+
+    expect(ctor).toHaveBeenCalledOnce();
+  });
+
+  it("reuses the same AudioContext across multiple calls", async () => {
+    const ctor = mockAudioContext();
+    window.AudioContext = ctor as unknown as typeof AudioContext;
+    const { playActionSound } = await import("./sound");
+
+    playActionSound("delete");
+    playActionSound("keep");
+
+    expect(ctor).toHaveBeenCalledOnce();
+  });
+});
diff --git a/src/sound.ts b/src/sound.ts
new file mode 100644
index 0000000..a33c867
--- /dev/null
+++ b/src/sound.ts
@@ -0,0 +1,125 @@
+import type { FileAction } from "./types";
+
+// Lazily created and reused across calls instead of a fresh AudioContext
+// per call. undefined = not yet attempted, null = attempted and
+// unavailable (a deterministic environment-support gap, not something
+// that resolves mid-session, so we don't retry construction on every call).
+let audioContext: AudioContext | null | undefined;
+
+function getAudioContext(): AudioContext | null {
+  if (audioContext !== undefined) return audioContext;
+
+  try {
+    const Ctor =
+      window.AudioContext ||
+      (window as unknown as { webkitAudioContext: typeof AudioContext }).webkitAudioContext;
+    audioContext = new Ctor();
+  } catch (_error) {
+    // Silently fail if audio context is not available
+    console.log("Audio feedback not available");
+    audioContext = null;
+  }
+
+  return audioContext;
+}
+
+// Delete sound: Descending "whoosh" effect (like something being thrown away)
+function playDeleteSound(ctx: AudioContext) {
+  const oscillator1 = ctx.createOscillator();
+  const oscillator2 = ctx.createOscillator();
+  const gainNode = ctx.createGain();
+  const filter = ctx.createBiquadFilter();
+
+  // Connect: oscillators -> filter -> gain -> destination
+  oscillator1.connect(filter);
+  oscillator2.connect(filter);
+  filter.connect(gainNode);
+  gainNode.connect(ctx.destination);
+
+  // Two oscillators for richer sound
+  oscillator1.frequency.setValueAtTime(300, ctx.currentTime);
+  oscillator1.frequency.exponentialRampToValueAtTime(50, ctx.currentTime + 0.3);
+  oscillator1.type = "sawtooth";
+
+  oscillator2.frequency.setValueAtTime(200, ctx.currentTime);
+  oscillator2.frequency.exponentialRampToValueAtTime(30, ctx.currentTime + 0.3);
+  oscillator2.type = "triangle";
+
+  // Low-pass filter for "whoosh" effect
+  filter.type = "lowpass";
+  filter.frequency.setValueAtTime(800, ctx.currentTime);
+  filter.frequency.exponentialRampToValueAtTime(200, ctx.currentTime + 0.3);
+
+  // Volume envelope
+  gainNode.gain.setValueAtTime(0.15, ctx.currentTime);
+  gainNode.gain.exponentialRampToValueAtTime(0.01, ctx.currentTime + 0.3);
+
+  oscillator1.start(ctx.currentTime);
+  oscillator1.stop(ctx.currentTime + 0.3);
+  oscillator2.start(ctx.currentTime);
+  oscillator2.stop(ctx.currentTime + 0.3);
+}
+
+// Keep sound: Ascending "chime" effect (like a positive confirmation)
+function playKeepSound(ctx: AudioContext) {
+  const oscillator1 = ctx.createOscillator();
+  const oscillator2 = ctx.createOscillator();
+  const oscillator3 = ctx.createOscillator();
+  const gainNode = ctx.createGain();
+  const filter = ctx.createBiquadFilter();
+
+  // Connect: oscillators -> filter -> gain -> destination
+  oscillator1.connect(filter);
+  oscillator2.connect(filter);
+  oscillator3.connect(filter);
+  filter.connect(gainNode);
+  gainNode.connect(ctx.destination);
+
+  // Three oscillators for a pleasant chord
+  oscillator1.frequency.setValueAtTime(523.25, ctx.currentTime); // C5
+  oscillator1.frequency.exponentialRampToValueAtTime(659.25, ctx.currentTime + 0.2); // E5
+  oscillator1.type = "sine";
+
+  oscillator2.frequency.setValueAtTime(659.25, ctx.currentTime); // E5
+  oscillator2.frequency.exponentialRampToValueAtTime(783.99, ctx.currentTime + 0.2); // G5
+  oscillator2.type = "sine";
+
+  oscillator3.frequency.setValueAtTime(783.99, ctx.currentTime); // G5
+  oscillator3.frequency.exponentialRampToValueAtTime(1046.5, ctx.currentTime + 0.2); // C6
+  oscillator3.type = "sine";
+
+  // High-pass filter for bright, clear sound
+  filter.type = "highpass";
+  filter.frequency.setValueAtTime(400, ctx.currentTime);
+
+  // Volume envelope with quick attack and decay
+  gainNode.gain.setValueAtTime(0, ctx.currentTime);
+  gainNode.gain.linearRampToValueAtTime(0.12, ctx.currentTime + 0.05);
+  gainNode.gain.exponentialRampToValueAtTime(0.01, ctx.currentTime + 0.25);
+
+  oscillator1.start(ctx.currentTime);
+  oscillator1.stop(ctx.currentTime + 0.25);
+  oscillator2.start(ctx.currentTime);
+  oscillator2.stop(ctx.currentTime + 0.25);
+  oscillator3.start(ctx.currentTime);
+  oscillator3.stop(ctx.currentTime + 0.25);
+}
+
+// Plays a short Web Audio sound for a keep/delete action. Always plays —
+// callers decide whether sound is wanted (e.g. a settings toggle) before
+// calling this.
+export function playActionSound(action: FileAction): void {
+  const ctx = getAudioContext();
+  if (!ctx) return;
+
+  try {
+    if (action === "delete") {
+      playDeleteSound(ctx);
+    } else {
+      playKeepSound(ctx);
+    }
+  } catch (_error) {
+    // Silently fail if playback itself throws
+    console.log("Audio feedback not available");
+  }
+}
diff --git a/src/types.ts b/src/types.ts
index 0276d27..58104af 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -4,8 +4,10 @@ import type { FileItem } from "../electron/ipc-types";
 
 export type { AppSettings, FileItem } from "../electron/ipc-types";
 
+export type FileAction = "delete" | "keep";
+
 export interface UndoAction {
-  action: "delete" | "keep";
+  action: FileAction;
   fileIndex: number;
   file: FileItem;
 }