Trying to use your microphone in an Oracle VirtualBox virtual machine, but getting only silence? This is a common hurdle, as audio input isn’t enabled by default and requires specific configuration. In this post, we are going to see what you can do if the Microphone is not working in an Oracle VirtualBox VM.
Why is my mic not working even though it’s on?
By default, VirtualBox is configured for audio output only. The audio input (microphone) controller is often set to “NULL Audio Driver” or left disabled, which isolates the guest OS from your host’s physical microphone. This requires you to manually change the VM’s settings and configure the guest operating system to recognize and use the virtual audio device.
Fix Microphone not working in Oracle VirtualBox VM
If the Microphone is not working in the Oracle VirtualBox VM, follow the solutions below.
- Enable Audio Input in VirtualBox VM Settings
- Install the Latest VirtualBox Extension Pack
- Configure the Guest OS Audio Input
- Change the Audio Controller to ICH AC97
- For Linux Guests: Install ALSA Utilities and Unmute Channels
Let us talk about them in detail.
1] Enable Audio Input in VirtualBox VM Settings
VirtualBox defaults to a NULL audio driver for input, effectively disconnecting the VM from your host’s microphone. Enabling the input and switching to the Intel HD Audio controller provides the guest OS with a modern, standardized virtual sound card that can properly relay audio signals from your physical hardware. To enable audio input in VirtualBox, follow the steps below.
- First, shut down your virtual machine completely; don’t put it in the Saved state.
- Then, select the VM, and click on Settings.
- Now, go to Audio on the left.
- Check the box for Enable Audio Input.
- Now, ensure that the Host Audio Driver is correct for your system (e.g., Windows Hosts typically use Windows DirectSound).
- Change the Audio Controller to Intel HD Audio. This is the most compatible modern controller.
- Click Ok.
Finally, check if the issue is resolved.
2] Install the Latest VirtualBox Extension Pack
The VirtualBox application lacks proprietary codecs and drivers required for advanced USB and audio device pass-through. The Extension Pack installs additional components, including critical firmware for the virtual audio controller, enabling full-featured communication between your host microphone and the guest OS.
Foremost, go to virtualbox.com, which is the official VirtualBox Downloads page, and under VirtualBox Extension Pack, click on Accept and download. This will start downloading the .vbox-extpack file and follow the installation prompts. Restart VirtualBox and then your VM.
3] Configure the Guest OS Audio Input
When the virtual microphone is correctly forwarded from the host, the guest operating system may default to a different or nonexistent input device; therefore, it is crucial to configure the Guest OS Audio Input. By manually selecting the VirtualBox Audio device, you direct the guest OS’s audio subsystem to capture sound from the correct virtual source, completing the final link in the audio pipeline.
Once your VirtualBox VM is running, open the guest operating system (e.g., Windows 10 or 11) and navigate to Settings > System > Sound. Under the Input section, select Microphone (VirtualBox Audio) or a similarly named device from the dropdown menu. Then use the Test your microphone feature to confirm it’s working, speak into the mic, and check for input level activity. If no microphone appears, ensure that audio input is enabled in the VM’s settings before launching the guest OS.
4] Change the Audio Controller to ICH AC97
The ICH AC97 controller uses an older, more widely supported audio standard with built-in drivers in virtually every modern operating system. While Intel HD Audio is more advanced, it can sometimes have driver compatibility issues within the guest OS. In contrast, the AC97 controller is almost guaranteed to be recognized and work immediately without additional configuration. To make this change, follow the steps below.
- Firstly, shut down your VM.
- Go to Settings > Audio.
- Change the Audio Controller from Intel HD Audio to ICH AC97.
- Start the VM.
Windows and most Linux distributions will automatically detect and install drivers for this legacy device.
Read: Fix VirtualBox USB not detected in Windows 11 computer
5] For Linux Guests: Install ALSA Utilities and Unmute Channels
ALSA sound driver on Linux often initializes input channels as muted by default for safety. Using alsamixer provides direct, low-level access to these driver settings, allowing you to manually unmute the specific virtual microphone channel and raise its capture level, which overrides the software-level mute that is blocking the audio signal.
Follow the steps mentioned below to do the same.
- Open Terminal in your Linux VM.
- Run the following command to install ALSA utilities.
Ubuntu/Debian: sudo apt install alsa-utils
Fedora/RHEL: sudo dnf install alsa-utils
- Run alsamixer to open the audio mixer.
- Press F4 to show capture devices.
- Use the arrow keys to select the Mic or Internal Mic channel.
- Press Spacebar to unmute it (you should see OO change to MM and then back to OO).
- Ensure the volume level is adequate.
- Press Esc to exit.
Finally, check if the issue is resolved.
That’s it!
Read: Fix Hyper-V Audio not working in Windows 11
How to enable microphone on VirtualBox?
To enable the microphone in VirtualBox, shut down the VM, open its Settings, go to the Audio tab, and check Enable Audio Input. Then, set the Audio Controller to Intel HD Audio (or “ICH AC97” if that fails) and finally, select the VirtualBox Audio device as the default input within your guest operating system’s sound settings.
Also Read: Share Local Resources with Hyper-V Virtual Machine in Windows 11.
