If you experience poor call quality, intermittent sound, or a microphone that does not work properly on your Q31i, it is usually related to the environment, wearing, the microphone, device permissions, or the call app settings. Most cases can be resolved by following the steps below in order.

Before You Start: Please make sure the headphone is powered on and connected to a device.

Troubleshooting Steps:

1. Environment and network:

1. Shorten the distance: Keep the phone within 3 meters of the headphone, and avoid walls or metal obstacles.

2. Turn off interference sources: Stay away from Wi-Fi routers, microwaves, and USB 3.0 devices (such as external hard drives).

3. Network signal: Confirm that the device's network signal is good.

2. Wearing check: Make sure the headphone is worn on the correct left/right side. Improper wearing can affect the microphone direction and thus call clarity.

3. Microphone cleaning: The call microphone is usually located on the outside of the headphone. If the microphone hole is blocked by dust, it can affect call quality. Clean the microphone area with a soft dry cloth or Blu-Tack—avoid liquid cleaners.

4. Device permissions: Go to the phone's "Settings" > "App management" > select the calling app > make sure "Microphone" and "Bluetooth" permissions are enabled. iPhone users can go to "Settings" > "Privacy" > "Microphone" to check.

5. Windows and multi-device:

1. Windows: When connecting the headphone to a Windows computer, set the microphone input to "Hands-Free" mode in the sound settings.

2. Multi-device protocol conflicts: Bluetooth headphones use different protocols for calls and music. If the headphone is connected to multiple devices (such as a phone and a computer) at the same time, protocol conflicts may cause call issues. Try disconnecting one of the devices.

6. Call app settings and permissions:

1. Some apps (such as WeChat or Zoom) may not be optimized for a specific headphone, which can prevent the microphone from working or cause intermittent sound. Check the call app's audio settings and make sure the headphone is selected as the microphone and audio device.

2. iOS: Go to "Settings" > "Privacy" > "Microphone" and confirm that the app's permissions are enabled. Android: Go to "Settings" > "App permissions" and confirm the app's microphone and Bluetooth permissions are enabled.

If you encounter any other issues or your issue has not been resolved, please contact us for further assistance.