How to fix WhatsApp call no voice error: Receiver cannot hear at other end

Numerous issues have been plaguing WhatsApp users on Android devices, while some users have been complaining about voice call issues, wherein the receiver cannot hear at the other end.

If you are one of the affected users, then you can try a simple fix outlined in the tutorial below, which requires the device to be pre-rooted. In case your Android device is not rooted, you need to obtain root access first, before you can install this fix.

Here is how you apply the fix for WhatsApp voice call issues in Android:

Step 1: Download and install ES File Explorer from the Google Play Store

Step 2: Launch the File Explorer app and swipe the device's screen from its left edge towards right to pull out the menu

Step 3: Go to Tools section and locate the root explorer option. Then click on its On/Off toggle button to enable it and grant permission if prompted.

Step 4: Navigate to system folder and tap on build.prop and then choose ES Note editor

Step 5: Tap on the 3-dot menu at top right and select Edit

Step 6: Then find and replace the value true with false for the following lines of code:

• Search for use.dedicated.device.for.viop=true and replace the value true with false. Hence, it would be: use.dedicated.device.for.viop=false
• Search for use.voice.path.for.pcm.voip=true and replace the value true with false here as well. Then the code will be: use.voice.path.for.pcm.voip=false

Step 7: Save and return to homescreen. Try calling your friend using WhatsApp now and it should work.

[Source: XDA]