diff --git a/1000-hours/public/audios/frustrate-uk.mp3 b/1000-hours/public/audios/frustrate-uk.mp3
new file mode 100644
index 00000000..d43debfd
Binary files /dev/null and b/1000-hours/public/audios/frustrate-uk.mp3 differ
diff --git a/1000-hours/public/audios/frustrate-us.mp3 b/1000-hours/public/audios/frustrate-us.mp3
new file mode 100644
index 00000000..b5ae2dd7
Binary files /dev/null and b/1000-hours/public/audios/frustrate-us.mp3 differ
diff --git a/1000-hours/public/jupyter-notebooks/edge-tts-valcab-pronounciation.ipynb b/1000-hours/public/jupyter-notebooks/edge-tts-valcab-pronounciation.ipynb
index b2e929ad..e53d4b2e 100644
--- a/1000-hours/public/jupyter-notebooks/edge-tts-valcab-pronounciation.ipynb
+++ b/1000-hours/public/jupyter-notebooks/edge-tts-valcab-pronounciation.ipynb
@@ -31,17 +31,25 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 2,
    "id": "9aad6634-e833-4ec4-b285-84e051329712",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Files created!\n"
+     ]
+    }
+   ],
    "source": [
     "import asyncio\n",
     "import edge_tts\n",
     "import pygame\n",
     "\n",
     "TEXT = \"\"\"\n",
-    "happy\n",
+    "frustrate\n",
     "\"\"\"\n",
     "\n",
     "Wordlist = TEXT.split(\",\")\n",
diff --git a/1000-hours/sounds-of-english/19-sptk.md b/1000-hours/sounds-of-english/19-sptk.md
index eeeaa942..f87e0df8 100644
--- a/1000-hours/sounds-of-english/19-sptk.md
+++ b/1000-hours/sounds-of-english/19-sptk.md
@@ -1,9 +1,10 @@
-# 2.2.7. `sp, st, sk`
+# 2.2.7. `sp, st, str, sk`
 
 `p, t, k` 这三个清辅音对应着三个浊辅音： `b, d, g`。
 
-需要注意的是，`p, t, k` 这三个清辅音在 `s` 之后的时候会发生 “浊化” 现象。
+需要注意的是，`p, t, k` 这三个清辅音在 `s` 之后的时候会发生 “浊化” 现象。另外请注意，`tr` 也会在 `s` 之后变成 `dr`。
 
 > * *speak* `/spiːk/` 实际上读作 `/sbiːk/`<span class="speak-word-inline" data-audio-uk="/audios/speak-uk.mp3" data-audio-us="/audios/speak-us.mp3"></span>
 > * *student* `/ˈstudənt/` 实际上读作 `/ˈsdudənt/`<span class="speak-word-inline" data-audio-uk="/audios/student-uk.mp3" data-audio-us="/audios/student-us.mp3"></span>
-> * *school* `/skuːl/` 实际上读作 `/sguːl/`<span class="speak-word-inline" data-audio-uk="/audios/school-uk.mp3" data-audio-us="/audios/school-us.mp3"></span>
\ No newline at end of file
+> * *school* `/skuːl/` 实际上读作 `/sguːl/`<span class="speak-word-inline" data-audio-uk="/audios/school-uk.mp3" data-audio-us="/audios/school-us.mp3"></span>
+> * *frustrate* `/ˈfrʌˌstreɪt/` 实际上读作 `/ˈfrʌˌsdreɪt/`<span class="speak-word-inline" data-audio-uk="/audios/frustrate-uk.mp3" data-audio-us="/audios/frustrate-us.mp3"></span>
\ No newline at end of file