# Sound on Android doesn't work

**URL:** <https://discourse.processing.org/t/sound-on-android-doesnt-work/17516>\
**Category:** Processing for Android\
**Created:** [February 2, 2020, 1:54pm UTC](https://discourse.processing.org/t/sound-on-android-doesnt-work/17516 "2020-02-02T13:54:53Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![ViZrd](https://avatars.discourse-cdn.com/v4/letter/v/cc9497/32.png) [@ViZrd](https://discourse.processing.org/u/ViZrd)\
**Post date:** [February 2, 2020, 1:54pm UTC](https://discourse.processing.org/t/sound-on-android-doesnt-work/17516/1 "2020-02-02T13:54:53Z")

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I tried the sound example ([https://processing.org/reference/libraries/sound/Sound.html](https://processing.org/reference/libraries/sound/Sound.html)) and while the app “worked”, as in- it runs on the device, no sound is generated.

I get the Processing console error:  
java.lang.NoClassDefFoundError: Failed resolution of: Landroid/media/AudioRecord$Builder;  
at processing.sound.JSynAndroidAudioDeviceManager$AndroidAudioInputStream.start(Unknown Source)  
at com.jsyn.engine.SynthesisEngine$EngineThread.run(Unknown Source)  
Caused by: java.lang.ClassNotFoundException: Didn’t find class “android.media.AudioRecord$Builder” on path: DexPathList[[zip file “/data/app/processing.test.musicnotes\_06b\_android-1/base.apk”],nativeLibraryDirectories=[/vendor/lib, /system/lib]]  
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)  
at java.lang.ClassLoader.loadClass(ClassLoader.java:511)  
at java.lang.ClassLoader.loadClass(ClassLoader.java:469)  
… 2 more  
Suppressed: java.lang.ClassNotFoundException: android.media.AudioRecord$Builder  
at java.lang.Class.classForName(Native Method)  
at java.lang.BootClassLoader.findClass(ClassLoader.java:781)  
at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)  
at java.lang.ClassLoader.loadClass(ClassLoader.java:504)  
… 3 more  
Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack available

How do I solve it? What am I doing wrong?

Something to do with my installation?  
I’m using Windows 10 & Processing 3.5.4  
Tried on a Moto X (1st Gen) .and a Xioami Redmi 5A (Where I don’t ger the error report “AndroidDevice: cannot find process id, console output will be disabled”