The situation when during an important call suddenly disappears sound, can unbalance any user. Smartphones line Xiaomi, Redmi and Poco are famous for excellent value for money, but software failures in the shell MIUI or HyperOS can lead to incorrect operation of audio modules. The user may face the fact that he does not hear the interlocutor, or, conversely, the interlocutor complains of complete silence on your part.
In most cases, the problem is not a physical breakdown, but a software conflict or a misconfiguration of the system. Voice audio codecs can freeze due to background processes or incorrectly updated drivers. Before you carry a device to the service center, it is worth conducting a comprehensive diagnostic of the software part, since this often solves the problem in a couple of minutes.
Sometimes the lack of sound is a consequence of noise cancellation, which completely silences the voice in an attempt to cut off background noise, and we can't rule out a banal connection to a Bluetooth headset that lies at the other end of the room while the phone continues to transmit sound there. Understanding the source of the problem is the key to quickly recovering communication.
⚠️ Note: If your smartphone has recently been in water or fallen from a height, software methods may not help.
Checking basic volume settings and modes
The first thing you need to do is make sure the volume settings are correct. There is a separation of volume levels in the MIUI and HyperOS shells for multimedia, calls and alarms, and often users turn down the multimedia sound and forget that the volume level of the speaker may have stayed at a minimum or been turned off.
When incoming or outgoing calls, use the side buttons to adjust the sound. A menu should appear on the screen where the slider is marked by the phone tube icon. Make sure it is raised to its maximum value. Also check if Do Not Disturb or Silent Mode is activated, which can block the audio accompaniment of the call.
Special attention should be paid to noise reduction settings. Some Xiaomi models with two microphones (main and optional for noise cancellation) may experience a software failure when the system silences the main channel. Try turning off the "Sound Improvement" or "Noise Cancelation" function in the sound settings, if this option is available in your firmware version.
It is not superfluous to check whether the device is connected to external audio outputs. Sometimes the phone "thinks" that it has headphones connected even if they are not physically present. This can be due to contamination of the 3.5 mm connector (if any) or software freezes the Bluetooth module. Forced shutting down Bluetooth in the "curtain" of notifications will help to eliminate this factor.
Conflicts with Bluetooth and third-party devices
Xiaomi’s smartphones are actively interacting with the smart ecosystem. If you have an app running in the background to control headphones or smartwatches, it can intercept the audio stream. Even if the headset is turned off, the system can try to route sound through it, creating the illusion of no sound in the speaker.
Check the list of paired devices in Bluetooth settings. If there are old or unused gadgets, try removing them from the list or temporarily disabling the Bluetooth function completely, which will force the output to switch to the main speaker.
If you use a third-party call app (like Google or Yandex), it may have its own audio routing settings. Try switching temporarily to Xiaomi’s standard Phone app to see if the problem persists.
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Try turning on and off flight mode (air mode) for 10 seconds, which will restart all radio modules, including the communication module, which often eliminates software "locks" in voice transmission.
Diagnostics of software failure and reboot
Accumulation of temporary files and errors in RAM can cause malfunctions in the work of audio drivers. Standard smartphone reboot often solves the problem, as it clears the cache of system processes and restarts services responsible for communication. Xiaomi is characterized by aggressive battery optimization, which sometimes kills the desired processes.
If a normal reboot didn't work, try a deeper method, Safe Mode, which only runs system applications, and if you have a sound in safe mode, it means that some app you installed is causing the problem, and you need to remove recently installed programs, especially those that have access to the microphone.
It is important to check for system updates. Xiaomi engineers regularly release patches that fix communication bugs. Go to Settings → About Phone → MIUI version and check for updates. Sometimes the problem is massive and only solved by the release of a new security patch.
☑️ Checklist of rapid diagnosis
Cleaning speakers and microphones from pollution
One of the most common causes of silent sound, or no sound, is banal dust, pile and dirt. The speaker grid at the top of the screen has microscopic holes that are easily clogged, and over time, the dust layer becomes an impenetrable membrane that blocks the sound.
Use a soft dry toothbrush or a special sticky tape (scotch) to clean the net, sweeping the dust out. It is strictly forbidden to use needles or sharp objects, as they easily pierce the speaker membrane, which will lead to its complete breakage.
Also check the bottom microphone (usually this small hole next to the charging connector or on the end).If you often carry your phone in your pocket without a cover, there is most pile accumulation. Gently blow the holes or use the pear to clean the optics to blow out the dust.
⚠️ Warning: Never use alcohol or other aggressive liquids to clean the speakers directly.The liquid can dissolve the glue holding the membrane or get inside the housing, causing a short circuit.
Reset network settings and return to factory settings
If the software failures are more profound, you may need to reset your network settings, which won’t delete your personal photos or contacts, but will return your Wi-Fi, Bluetooth, and cellular settings to factory values, which often helps if your codec or carrier profile settings are lost.
To reset, go to Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth. Confirm and restart the device. Once turned on, you will need to re-enter passwords from Wi-Fi networks.
In extreme cases, if nothing works, you have to completely reset to the factory settings (Hard Reset), which will completely remove all data from the phone, so be sure to back up important files to the cloud or to your computer. Once reset, the phone will be as new, and if the sound does not appear even on a clean system, the problem is precisely hardware.
How to make a backup copy before resetting?
Hardware malfunctions and symptom table
When software is exhausted, you have to consider physical failure: In low-end and mid-range Redmi and Poco smartphones, speaker plumes can move away from the board when hit by a strong impact, and contact oxidation when moisture is injected.
Below is a table that helps classify the problem by symptoms:
| Symptoms. | Probable cause | Method of decision |
|---|---|---|
| The sound is only on speakerphone. | Failure of the conversational speaker | Replacement of the top speaker |
| The interviewer hears an echo or whistle | The problem with the noise reduction microphone | Cleaning the lower microphone or replacing the plume |
| The sound came after the fall. | plume effluent or speaker crack | Disassembly and soldering of contacts |
| The sound disappeared after the software update | Firmware bug | Reverse version or wait for a patch |
If you see symptoms in the first two rows of the table, the probability of hardware repair is more than 80%. In cases of falls or water, self-repair without experience can lead to aggravation, for example, to damage to the screen plume when trying to get to the speaker.
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If after a complete reset of the system (Hard Reset) the sound did not appear, further software manipulations are meaningless - diagnostics are required in the service center.
Using the Engineering Menu for Testing
Android smartphones, including Xiaomi, have a hidden engineering menu for diagnosing hardware components, which allows you to check each microphone and speaker separately, which helps to precisely localize the malfunction.
On the menu that opens (CIT) You need to find the audio section (Receiver, Speaker, Microphone) and run a test, and the phone will ask you to say a phrase or listen to a test sound. If there's sound in this menu, then the hardware is fine, and the system is in trouble or you're not listening to a test sound. SIM-If there's no sound even on the engineering menu, that's a direct route to service.
Sometimes it helps to flash the modem, but it is a complex procedure that requires an unlocked bootloader and skills to work with Fastboot. It is safer for the average user to limit himself to resetting the network settings and checking the relevance of the base station version through the code ##4636## -> Phone Information -> Refresh networks.