diff --git a/lib/notification-sound.ts b/lib/notification-sound.ts
index 36589e318..f3ab179ea 100644
--- a/lib/notification-sound.ts
+++ b/lib/notification-sound.ts
@@ -3,6 +3,8 @@ import { withBasePath } from '@/lib/browser-navigation';
 
 export type NotificationSoundChoice = 'default' | 'cheerful' | 'involved' | 'swift' | 'relax';
 
+// 'default' is the beep. It was the default sound until Involved replaced
+// it, and keeps its id so stored and synced choices still match.
 export const NOTIFICATION_SOUNDS: { id: NotificationSoundChoice; file?: string }[] = [
   { id: 'default' },
   { id: 'cheerful', file: '/notification/cheerful-527.mp3' },
@@ -53,7 +55,7 @@ function playFile(file: string) {
 
 export function playNotificationSound(sound?: NotificationSoundChoice) {
   try {
-    const choice = sound ?? 'default';
+    const choice = sound ?? 'involved';
     const entry = NOTIFICATION_SOUNDS.find((s) => s.id === choice);
 
     if (entry?.file) {
diff --git a/locales/ar/common.json b/locales/ar/common.json
index 96ad8aefc..abb0b3c3a 100644
--- a/locales/ar/common.json
+++ b/locales/ar/common.json
@@ -1633,7 +1633,7 @@
     "notifications": {
       "test_sound": "اختبار صوت الإشعار",
       "sounds": {
-        "default": "افتراضي (تنبيه)",
+        "default": "تنبيه",
         "cheerful": "مرح",
         "involved": "متفاعل",
         "swift": "إيماءة سريعة",
diff --git a/locales/ca/common.json b/locales/ca/common.json
index b61af665e..7a79939d2 100644
--- a/locales/ca/common.json
+++ b/locales/ca/common.json
@@ -1633,7 +1633,7 @@
     "notifications": {
       "test_sound": "Prova el so de notificació",
       "sounds": {
-        "default": "Per defecte (bip)",
+        "default": "Bip",
         "cheerful": "Alegre",
         "involved": "Elaborat",
         "swift": "Gest ràpid",
diff --git a/locales/cs/common.json b/locales/cs/common.json
index a12b48d06..2bb0818cc 100644
--- a/locales/cs/common.json
+++ b/locales/cs/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "Otestovat zvuk oznámení",
       "sounds": {
-        "default": "Výchozí (Pípnutí)",
+        "default": "Pípnutí",
         "cheerful": "Veselý",
         "involved": "Dynamický",
         "swift": "Rychlý",
diff --git a/locales/da/common.json b/locales/da/common.json
index d46d60f9e..dad06620e 100644
--- a/locales/da/common.json
+++ b/locales/da/common.json
@@ -1633,7 +1633,7 @@
     "notifications": {
       "test_sound": "Test notifikationslyd",
       "sounds": {
-        "default": "Standard (Bip)",
+        "default": "Bip",
         "cheerful": "Glad",
         "involved": "Engageret",
         "swift": "Hurtig gestus",
diff --git a/locales/de/common.json b/locales/de/common.json
index 9a484997d..5f0adf407 100644
--- a/locales/de/common.json
+++ b/locales/de/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "Benachrichtigungston testen",
       "sounds": {
-        "default": "Standard (Piepton)",
+        "default": "Piepton",
         "cheerful": "Fröhlich",
         "involved": "Aufwendig",
         "swift": "Schnelle Geste",
diff --git a/locales/en/common.json b/locales/en/common.json
index e30e2d5c8..243c1a1f8 100644
--- a/locales/en/common.json
+++ b/locales/en/common.json
@@ -1633,7 +1633,7 @@
     "notifications": {
       "test_sound": "Test notification sound",
       "sounds": {
-        "default": "Default (Beep)",
+        "default": "Beep",
         "cheerful": "Cheerful",
         "involved": "Involved",
         "swift": "Swift Gesture",
diff --git a/locales/es/common.json b/locales/es/common.json
index b910bc0d2..ae9bda45e 100644
--- a/locales/es/common.json
+++ b/locales/es/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "Probar sonido de notificación",
       "sounds": {
-        "default": "Predeterminado (Pitido)",
+        "default": "Pitido",
         "cheerful": "Alegre",
         "involved": "Elaborado",
         "swift": "Gesto rápido",
diff --git a/locales/et/common.json b/locales/et/common.json
index 4513dcc2d..1e4d42b81 100644
--- a/locales/et/common.json
+++ b/locales/et/common.json
@@ -1633,7 +1633,7 @@
     "notifications": {
       "test_sound": "Testi teavitusheli",
       "sounds": {
-        "default": "Vaikimisi (piiks)",
+        "default": "Piiks",
         "cheerful": "Rõõmus",
         "involved": "Elav",
         "swift": "Kiire liigutus",
diff --git a/locales/fa/common.json b/locales/fa/common.json
index 03c0d0667..65663686c 100644
--- a/locales/fa/common.json
+++ b/locales/fa/common.json
@@ -1633,7 +1633,7 @@
     "notifications": {
       "test_sound": "تست صدای اعلان",
       "sounds": {
-        "default": "پیش‌فرض (بیپ)",
+        "default": "بیپ",
         "cheerful": "شاد",
         "involved": "درگیر",
         "swift": "سریع",
diff --git a/locales/fr/common.json b/locales/fr/common.json
index 2f8d73ee6..514b20378 100644
--- a/locales/fr/common.json
+++ b/locales/fr/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "Tester le son de notification",
       "sounds": {
-        "default": "Par défaut (Bip)",
+        "default": "Bip",
         "cheerful": "Joyeux",
         "involved": "Élaboré",
         "swift": "Geste rapide",
diff --git a/locales/he/common.json b/locales/he/common.json
index 0988e6910..a7baace39 100644
--- a/locales/he/common.json
+++ b/locales/he/common.json
@@ -1595,7 +1595,7 @@
     "notifications": {
       "test_sound": "צליל הודעת בדיקה",
       "sounds": {
-        "default": "ברירת מחדל (ביפ)",
+        "default": "ביפ",
         "cheerful": "עליז",
         "involved": "מעורב",
         "swift": "מחווה מהירה",
diff --git a/locales/hu/common.json b/locales/hu/common.json
index 12db95bfd..d719d7f79 100644
--- a/locales/hu/common.json
+++ b/locales/hu/common.json
@@ -1633,7 +1633,7 @@
     "notifications": {
       "test_sound": "Értesítési hang tesztelése",
       "sounds": {
-        "default": "Alapértelmezett (sípolás)",
+        "default": "Sípolás",
         "cheerful": "Vidám",
         "involved": "Lelkes",
         "swift": "Gyors mozdulat",
diff --git a/locales/it/common.json b/locales/it/common.json
index 446b82fe7..fd2423aa8 100644
--- a/locales/it/common.json
+++ b/locales/it/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "Testa il suono di notifica",
       "sounds": {
-        "default": "Predefinito (Bip)",
+        "default": "Bip",
         "cheerful": "Allegro",
         "involved": "Elaborato",
         "swift": "Gesto veloce",
diff --git a/locales/ja/common.json b/locales/ja/common.json
index 637a4fcc2..e077191e5 100644
--- a/locales/ja/common.json
+++ b/locales/ja/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "通知音をテスト",
       "sounds": {
-        "default": "デフォルト（ビープ）",
+        "default": "ビープ",
         "cheerful": "チアフル",
         "involved": "インボルブド",
         "swift": "スウィフトジェスチャー",
diff --git a/locales/ko/common.json b/locales/ko/common.json
index d0cd27ff6..bf85cc43c 100644
--- a/locales/ko/common.json
+++ b/locales/ko/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "알림음 테스트",
       "sounds": {
-        "default": "기본 (비프음)",
+        "default": "비프음",
         "cheerful": "밝게",
         "involved": "경쾌하게",
         "swift": "빠르게",
diff --git a/locales/lv/common.json b/locales/lv/common.json
index b58366a1f..1d670880b 100644
--- a/locales/lv/common.json
+++ b/locales/lv/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "Pārbaudīt paziņojuma skaņu",
       "sounds": {
-        "default": "Noklusējuma (Signāls)",
+        "default": "Signāls",
         "cheerful": "Priecīgs",
         "involved": "Iesaistošs",
         "swift": "Ātrs",
diff --git a/locales/mn/common.json b/locales/mn/common.json
index 9a8b94dc7..d9759deed 100644
--- a/locales/mn/common.json
+++ b/locales/mn/common.json
@@ -1633,7 +1633,7 @@
     "notifications": {
       "test_sound": "Туршилтын мэдэгдлийн дуу",
       "sounds": {
-        "default": "Өгөгдмөл (Дохио)",
+        "default": "Дохио",
         "cheerful": "Хөгжилтэй",
         "involved": "Оролцсон",
         "swift": "Шуурхай зангаа",
diff --git a/locales/nb/common.json b/locales/nb/common.json
index 0df5cb3bd..2fafd10a2 100644
--- a/locales/nb/common.json
+++ b/locales/nb/common.json
@@ -1633,7 +1633,7 @@
     "notifications": {
       "test_sound": "Test varslingslyden",
       "sounds": {
-        "default": "Standard (pip)",
+        "default": "Pip",
         "cheerful": "Munter",
         "involved": "Engasjert",
         "swift": "Rask",
diff --git a/locales/nl/common.json b/locales/nl/common.json
index 609f28101..27e3bfcee 100644
--- a/locales/nl/common.json
+++ b/locales/nl/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "Meldingsgeluid testen",
       "sounds": {
-        "default": "Standaard (Pieptoon)",
+        "default": "Pieptoon",
         "cheerful": "Vrolijk",
         "involved": "Uitgebreid",
         "swift": "Snel gebaar",
diff --git a/locales/pl/common.json b/locales/pl/common.json
index 09942dce0..be06b4fda 100644
--- a/locales/pl/common.json
+++ b/locales/pl/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "Przetestuj dźwięk powiadomienia",
       "sounds": {
-        "default": "Domyślny (Beep)",
+        "default": "Beep",
         "cheerful": "Pogodny",
         "involved": "Dynamiczny",
         "swift": "Szybki gest",
diff --git a/locales/pt/common.json b/locales/pt/common.json
index e160a52d4..596a7a982 100644
--- a/locales/pt/common.json
+++ b/locales/pt/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "Testar som de notificação",
       "sounds": {
-        "default": "Padrão (Bipe)",
+        "default": "Bipe",
         "cheerful": "Alegre",
         "involved": "Elaborado",
         "swift": "Gesto rápido",
diff --git a/locales/ro/common.json b/locales/ro/common.json
index 1abc36a8e..b1d462048 100644
--- a/locales/ro/common.json
+++ b/locales/ro/common.json
@@ -1633,7 +1633,7 @@
     "notifications": {
       "test_sound": "Testați sunetul de notificare",
       "sounds": {
-        "default": "Implicit (Bip)",
+        "default": "Bip",
         "cheerful": "Vesel",
         "involved": "Implicat",
         "swift": "Gest rapid",
diff --git a/locales/ru/common.json b/locales/ru/common.json
index cd07676b6..a5e3acf71 100644
--- a/locales/ru/common.json
+++ b/locales/ru/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "Проверить звук уведомления",
       "sounds": {
-        "default": "По умолчанию (Сигнал)",
+        "default": "Сигнал",
         "cheerful": "Радостный",
         "involved": "Вовлечённый",
         "swift": "Быстрый жест",
diff --git a/locales/sk/common.json b/locales/sk/common.json
index 3bfd4da76..dcb14ff6a 100644
--- a/locales/sk/common.json
+++ b/locales/sk/common.json
@@ -1633,7 +1633,7 @@
     "notifications": {
       "test_sound": "Otestovať zvuk oznámenia",
       "sounds": {
-        "default": "Predvolený (Pípnutie)",
+        "default": "Pípnutie",
         "cheerful": "Veselý",
         "involved": "Dynamický",
         "swift": "Rýchly",
diff --git a/locales/th/common.json b/locales/th/common.json
index d70543745..881359531 100644
--- a/locales/th/common.json
+++ b/locales/th/common.json
@@ -4070,7 +4070,7 @@
     "notifications": {
       "test_sound": "ทดสอบเสียงแจ้งเตือน",
       "sounds": {
-        "default": "ค่าเริ่มต้น (เสียงบี๊บ)",
+        "default": "เสียงบี๊บ",
         "cheerful": "ร่าเริง (Cheerful)",
         "involved": "กระตือรือร้น (Involved)",
         "swift": "รวดเร็ว (Swift Gesture)",
diff --git a/locales/tr/common.json b/locales/tr/common.json
index 752227bec..50e40029e 100644
--- a/locales/tr/common.json
+++ b/locales/tr/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "Bildirim sesini test et",
       "sounds": {
-        "default": "Varsayılan (Bip)",
+        "default": "Bip",
         "cheerful": "Neşeli",
         "involved": "Odaklı",
         "swift": "Hızlı Jest",
diff --git a/locales/uk/common.json b/locales/uk/common.json
index cc6369150..25c7531de 100644
--- a/locales/uk/common.json
+++ b/locales/uk/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "Тестовий звук сповіщення",
       "sounds": {
-        "default": "За замовчуванням (звуковий сигнал)",
+        "default": "Звуковий сигнал",
         "cheerful": "Веселий",
         "involved": "Залучений",
         "swift": "Швидкий жест",
diff --git a/locales/zh-TW/common.json b/locales/zh-TW/common.json
index 9e1232a72..031e647f1 100644
--- a/locales/zh-TW/common.json
+++ b/locales/zh-TW/common.json
@@ -1633,7 +1633,7 @@
     "notifications": {
       "test_sound": "測試通知聲音",
       "sounds": {
-        "default": "預設（蜂鳴聲）",
+        "default": "蜂鳴聲",
         "cheerful": "快樂",
         "involved": "沉浸",
         "swift": "輕快手勢",
diff --git a/locales/zh/common.json b/locales/zh/common.json
index 260c4c941..bc30a8250 100644
--- a/locales/zh/common.json
+++ b/locales/zh/common.json
@@ -1630,7 +1630,7 @@
     "notifications": {
       "test_sound": "测试通知声音",
       "sounds": {
-        "default": "默认（蜂鸣声）",
+        "default": "蜂鸣声",
         "cheerful": "快乐",
         "involved": "沉浸",
         "swift": "轻快手势",
diff --git a/stores/__tests__/settings-notification-sound.test.ts b/stores/__tests__/settings-notification-sound.test.ts
new file mode 100644
index 000000000..7a65b43f3
--- /dev/null
+++ b/stores/__tests__/settings-notification-sound.test.ts
@@ -0,0 +1,50 @@
+import { beforeEach, describe, it, expect } from 'vitest';
+import { useSettingsStore, migrateSettings } from '../settings-store';
+
+// The new mail sound defaults to Involved; 'default' is the beep, which was
+// the default before.
+
+const migrate = (state: Record<string, unknown>, version: number) =>
+  migrateSettings(state, version) as unknown as Record<string, unknown>;
+
+describe('notification sound default', () => {
+  beforeEach(() => {
+    useSettingsStore.getState().resetToDefaults();
+  });
+
+  it('plays Involved on a fresh install', () => {
+    expect(useSettingsStore.getState().notificationSoundChoice).toBe('involved');
+  });
+
+  it('moves a beep the user never picked to Involved', () => {
+    expect(migrate({ notificationSoundChoice: 'default', explicitSettings: [] }, 9).notificationSoundChoice).toBe('involved');
+  });
+
+  it('keeps a beep the user picked', () => {
+    const out = migrate({ notificationSoundChoice: 'default', explicitSettings: ['notificationSoundChoice'] }, 9);
+    expect(out.notificationSoundChoice).toBe('default');
+  });
+
+  it('keeps any other sound the user picked', () => {
+    expect(migrate({ notificationSoundChoice: 'relax', explicitSettings: [] }, 9).notificationSoundChoice).toBe('relax');
+  });
+
+  it('does not take the beep from before explicitSettings existed as chosen', () => {
+    const out = migrate({ notificationSoundChoice: 'default' }, 7);
+    expect(out.notificationSoundChoice).toBe('involved');
+    expect(out.explicitSettings).not.toContain('notificationSoundChoice');
+  });
+
+  it('moves the beep along in a server copy or export from an older build', () => {
+    const store = useSettingsStore.getState();
+    expect(store.importSettings(JSON.stringify({ notificationSoundChoice: 'default', explicitSettings: [] }))).toBe(true);
+    expect(useSettingsStore.getState().notificationSoundChoice).toBe('involved');
+
+    expect(store.importSettings(JSON.stringify({ notificationSoundChoice: 'default' }))).toBe(true);
+    expect(useSettingsStore.getState().notificationSoundChoice).toBe('involved');
+    expect(useSettingsStore.getState().explicitSettings).not.toContain('notificationSoundChoice');
+
+    expect(store.importSettings(JSON.stringify({ notificationSoundChoice: 'default', explicitSettings: ['notificationSoundChoice'] }))).toBe(true);
+    expect(useSettingsStore.getState().notificationSoundChoice).toBe('default');
+  });
+});
diff --git a/stores/settings-store.ts b/stores/settings-store.ts
index 66dc7edcf..810d45a85 100644
--- a/stores/settings-store.ts
+++ b/stores/settings-store.ts
@@ -942,7 +942,7 @@ const DEFAULT_SETTINGS = {
   // Email Notifications
   emailNotificationsEnabled: true,
   emailNotificationSound: true,
-  notificationSoundChoice: 'default' as NotificationSoundChoice,
+  notificationSoundChoice: 'involved' as NotificationSoundChoice,
   pushNotifyInboxOnly: false,
   notificationMutes: EMPTY_NOTIFICATION_MUTES,
   pushRelayUrl: '',
@@ -1495,6 +1495,7 @@ export const useSettingsStore = create<SettingsState>()(
             settings.protocolOpenMode = settings.protocolMailtoOpenMode;
           }
           migrateAnimationsSetting(settings);
+          migrateNotificationSoundDefault(settings);
 
           // Apply settings, noting which keys were taken over for the
           // onSettingsImport hook.
@@ -1896,7 +1897,7 @@ export const useSettingsStore = create<SettingsState>()(
     },
     {
       name: 'settings-storage',
-      version: 9,
+      version: 10,
       migrate: migrateSettings,
       onRehydrateStorage: () => {
         return (state) => {
@@ -1994,6 +1995,9 @@ export function migrateSettings(persisted: unknown, version: number): SettingsSt
         if (version < 6 || !isPlainRecord(state.preferredIdentityIds)) {
           state.preferredIdentityIds = {};
         }
+        // Before the v8 step: a beep from before explicitSettings existed was
+        // the default then, and must not be taken as chosen below.
+        migrateNotificationSoundDefault(state);
         // v8: admin policy defaults (#1248) skip settings the user chose.
         // Earlier builds did not record that, so a setting that differs from
         // the build default is taken as chosen.
@@ -2020,6 +2024,18 @@ export function migrateAnimationsSetting(state: Record<string, unknown>): void {
   }
 }
 
+/**
+ * v10: the new mail sound defaults to Involved instead of the beep. A beep
+ * the user never picked was only the old default and moves to Involved; one
+ * they picked stays. Imports and server copies from older builds still
+ * carry the beep and go through this too.
+ */
+export function migrateNotificationSoundDefault(state: Record<string, unknown>): void {
+  if (state.notificationSoundChoice !== 'default') return;
+  const chosen = Array.isArray(state.explicitSettings) && state.explicitSettings.includes('notificationSoundChoice');
+  if (!chosen) state.notificationSoundChoice = 'involved';
+}
+
 // Helper functions to apply settings to DOM
 
 /** The settings applyAccessibilityTo() writes onto <html>. */