diff --git a/src/components/AudioDetail.vue b/src/components/AudioDetail.vue
index 9f92258e99..48c23008c1 100644
--- a/src/components/AudioDetail.vue
+++ b/src/components/AudioDetail.vue
@@ -176,11 +176,11 @@ const hotkeyMap = new Map<HotkeyAction, () => HotkeyReturnType>([
       if (
         !uiLocked.value &&
         store.getters.ACTIVE_AUDIO_KEY &&
-        store.state.audioPlayStartPoint !== undefined
+        store.getters.AUDIO_PLAY_START_POINT !== undefined
       ) {
         store.dispatch("COMMAND_RESET_SELECTED_MORA_PITCH_AND_LENGTH", {
           audioKey: store.getters.ACTIVE_AUDIO_KEY,
-          accentPhraseIndex: store.state.audioPlayStartPoint,
+          accentPhraseIndex: store.getters.AUDIO_PLAY_START_POINT,
         });
       }
     },
@@ -221,7 +221,7 @@ const activePointScrollMode = computed(() => store.state.activePointScrollMode);
 // 再生開始アクセント句
 const startPoint = computed({
   get: () => {
-    return store.state.audioPlayStartPoint;
+    return store.getters.AUDIO_PLAY_START_POINT;
   },
   set: (startPoint) => {
     store.dispatch("SET_AUDIO_PLAY_START_POINT", { startPoint });
diff --git a/src/store/audio.ts b/src/store/audio.ts
index ccf8e679ca..14d9b22f77 100644
--- a/src/store/audio.ts
+++ b/src/store/audio.ts
@@ -256,8 +256,6 @@ export const audioStoreState: AudioStoreState = {
   audioItems: {},
   audioKeys: [],
   audioStates: {},
-  // audio elementの再生オフセット
-  audioPlayStartPoint: undefined,
   nowPlayingContinuously: false,
 };
 
@@ -294,6 +292,29 @@ export const audioStore = createPartialStore<AudioStoreTypes>({
     },
   },
 
+  /**
+   * audio elementの再生オフセット。
+   * 選択+削除 や 挿入+選択+元に戻す などを行った場合でも範囲外にならないようにクランプする。
+   * ACTIVE_AUDIO_KEYがundefinedのときはundefinedを返す。
+   */
+  AUDIO_PLAY_START_POINT: {
+    getter(state, getters) {
+      const audioPlayStartPoint = state._audioPlayStartPoint;
+      if (
+        audioPlayStartPoint == undefined ||
+        getters.ACTIVE_AUDIO_KEY == undefined
+      ) {
+        return undefined;
+      }
+      const length =
+        state.audioItems[getters.ACTIVE_AUDIO_KEY].query?.accentPhrases.length;
+      if (length == undefined) {
+        return undefined;
+      }
+      return Math.max(0, Math.min(length - 1, audioPlayStartPoint));
+    },
+  },
+
   LOAD_CHARACTER: {
     action: createUILockAction(async ({ commit, dispatch }, { engineId }) => {
       const speakers = await dispatch("INSTANTIATE_ENGINE_CONNECTOR", {
@@ -538,7 +559,7 @@ export const audioStore = createPartialStore<AudioStoreTypes>({
 
   SET_AUDIO_PLAY_START_POINT: {
     mutation(state, { startPoint }: { startPoint?: number }) {
-      state.audioPlayStartPoint = startPoint;
+      state._audioPlayStartPoint = startPoint;
     },
     action({ commit }, { startPoint }: { startPoint?: number }) {
       commit("SET_AUDIO_PLAY_START_POINT", { startPoint });
@@ -1762,7 +1783,7 @@ export const audioStore = createPartialStore<AudioStoreTypes>({
   PLAY_AUDIO_BLOB: {
     action: createUILockAction(
       async (
-        { state, commit, dispatch },
+        { getters, commit, dispatch },
         { audioBlob, audioKey }: { audioBlob: Blob; audioKey?: AudioKey }
       ) => {
         commit("SET_AUDIO_SOURCE", { audioBlob });
@@ -1774,7 +1795,8 @@ export const audioStore = createPartialStore<AudioStoreTypes>({
           });
           if (accentPhraseOffsets.length === 0)
             throw new Error("accentPhraseOffsets.length === 0");
-          const startTime = accentPhraseOffsets[state.audioPlayStartPoint ?? 0];
+          const startTime =
+            accentPhraseOffsets[getters.AUDIO_PLAY_START_POINT ?? 0];
           if (startTime === undefined) throw Error("startTime === undefined");
           // 小さい値が切り捨てられることでフォーカスされるアクセントフレーズが一瞬元に戻るので、
           // 再生に影響のない程度かつ切り捨てられない値を加算する
@@ -1803,9 +1825,9 @@ export const audioStore = createPartialStore<AudioStoreTypes>({
   },
 
   PLAY_CONTINUOUSLY_AUDIO: {
-    action: createUILockAction(async ({ state, commit, dispatch }) => {
+    action: createUILockAction(async ({ state, getters, commit, dispatch }) => {
       const currentAudioKey = state._activeAudioKey;
-      const currentAudioPlayStartPoint = state.audioPlayStartPoint;
+      const currentAudioPlayStartPoint = getters.AUDIO_PLAY_START_POINT;
 
       let index = 0;
       if (currentAudioKey !== undefined) {
diff --git a/src/store/type.ts b/src/store/type.ts
index 48cbbc368e..b9e8e881f9 100644
--- a/src/store/type.ts
+++ b/src/store/type.ts
@@ -130,7 +130,7 @@ export type AudioStoreState = {
   audioStates: Record<AudioKey, AudioState>;
   _activeAudioKey?: AudioKey;
   _selectedAudioKeys?: AudioKey[];
-  audioPlayStartPoint?: number;
+  _audioPlayStartPoint?: number;
   nowPlayingContinuously: boolean;
 };
 
@@ -151,6 +151,10 @@ export type AudioStoreTypes = {
     getter(audioKey: AudioKey): boolean;
   };
 
+  AUDIO_PLAY_START_POINT: {
+    getter: number | undefined;
+  };
+
   LOAD_CHARACTER: {
     action(payload: { engineId: EngineId }): void;
   };
diff --git a/tests/unit/store/Vuex.spec.ts b/tests/unit/store/Vuex.spec.ts
index c32a665624..b6863137a5 100644
--- a/tests/unit/store/Vuex.spec.ts
+++ b/tests/unit/store/Vuex.spec.ts
@@ -35,7 +35,6 @@ describe("store/vuex.js test", () => {
         audioItems: {},
         audioKeys: [],
         audioStates: {},
-        audioPlayStartPoint: 0,
         uiLockCount: 0,
         dialogLockCount: 0,
         reloadingLock: false,
@@ -209,7 +208,6 @@ describe("store/vuex.js test", () => {
     assert.isEmpty(store.state.audioKeys);
     assert.isObject(store.state.audioStates);
     assert.isEmpty(store.state.audioStates);
-    assert.equal(store.state.audioPlayStartPoint, 0);
     assert.equal(store.state.uiLockCount, 0);
     assert.equal(store.state.nowPlayingContinuously, false);
     assert.isArray(store.state.undoCommands);