1. Update NDK & CMAKE
2. Download eSpeak-ng & Extract 
3. Create a folder android-build
4. open CMD and navigate to cd android-build
5. Run (Make sure to update the links)

"C:\Users\xxx\AppData\Local\Android\Sdk\cmake\xxx\bin\cmake.exe" -G Ninja ^
 -DCMAKE_MAKE_PROGRAM=C:\Users\xxx\AppData\Local\Android\Sdk\cmake\xxx\bin\ninja.exe ^
 -DCMAKE_TOOLCHAIN_FILE=C:\Users\xxx\AppData\Local\Android\Sdk\ndk\xxxx\build\cmake\android.toolchain.cmake ^
 -DANDROID_ABI=arm64-v8a ^
 -DANDROID_PLATFORM=android-21 ^
 -DANDROID_STL=c++_shared ^
 -DBUILD_SHARED_LIBS=ON ^
 ..

6. Close cmd and Run as Administrator and Navigate to the android-build folder

7. Run the command
"C:\Users\xxx\AppData\Local\Android\Sdk\cmake\xxx\bin\cmake.exe" --build .

8. Go to the folder
...\espeak-ng\android-build\src\libespeak-ng

You need is : libespeak-ng.so