If you have set all the attributes and audio source correctly, then this can be a security issue.
Add the following in your index.html.
<meta http-equiv="Content-Security-Policy" content="default-src 'self' https://appvipswi.easwi.it; script-src 'self' 'unsafe-inline'; media-src 'self'">
Set the AndroidManifest.xml as
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.RECORD_AUDIO" /> <uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />