Xiaomi’s modern smartphones are equipped with advanced sound processing algorithms that often remain hidden from the eyes of the average user. POCO When people complain about background noise, wind or echoes during a conversation, they don't even know that the interference suppression function can be activated or improved. MIUI HyperOS is constantly changing.
In this article, we’ll take a closer look at where to find noise reduction in Xiaomi, how it works at the hardware and software level, and how to improve voice quality. You’ll learn about hidden engineering menus, Bluetooth codec settings for wireless headsets, and specialized applications that help you achieve studio-wide sound clarity. Understanding these mechanisms will help you avoid embarrassing situations in business correspondence or when recording important content.
Now, it's worth noting that the way this works is very different depending on whether you're using a built-in microphone on your phone or an external headset. The first is digital signal processing (DSP), which is software-based to cut off frequencies that are not typical of human speech. The second is Active Noise Cancellation (ANC) technology, which requires separate activation, and we'll go through both scenarios in as much detail as possible.
Basic setting of the built-in microphone in the system
By default, Xiaomi smartphones already activate the noise reduction system at the firmware level and works automatically. However, in some regions or versions of the MIUI shell, there are additional options to enhance this effect or, conversely, turn it off for recording atmospheric video. To access the basic audio settings, go to the Settings → Sound and Vibration menu. Here you will find volume sliders for different use scenarios.
Special attention should be paid to the section related to recording quality. If you use a recorder or a camera, algorithms can aggressively cut down low frequencies, which makes voice unnatural. New versions of HyperOS have a feature called "Audio Zoom" or "Focus on Voice," which is actually advanced noise cancellation. It is available in the Camera app in Video mode and is indicated by the microphone icon.
It's important to understand that standard phone settings don't always allow you to fine-tune the sensitivity of the microphone. The system relies on pre-set profiles that may not work properly in high winds or in a very noisy room, such as a subway or construction site. In such cases, automation can make mistakes and mistake the speaker's voice for background noise, cropping the endings of phrases.
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Use the "Speak" mode only when absolutely necessary: the second microphone responsible for noise cancellation is located on the upper end and can be clogged with dust, which reduces the efficiency of sound cleaning.
For most users, standard functionality is enough, but if you blog or call frequently from noisy places, it is worth considering deeper customization methods. They require interference with system settings or using third-party software, which we will discuss in the next sections. Don't be afraid to experiment with settings, because you can return the original values at any time.
Activation of noise reduction in Bluetooth headphones
The situation with wireless headsets, especially the Xiaomi and Redmi Buds brand, looks different. Here, noise cancellation (ANC) is a physical function that must be activated manually through a special application. The built-in Android or MIUI settings often do not display the ANC switch in the notification curtain for third-party headphones, requiring the installation of branded software.
To manage these options, you will need a Xiaomi Earbuds app or Mi Buds M8 (depending on the model). Once you connect the headset and log in to the device menu, you will find a Noise Reduction switch. It can work in several modes: active (complete drowning out external sounds), transparency (missing ambient sounds), and turned off. The choice of mode depends on your current location.
- 🎧 Regime. ANC: Perfect for a plane, train or noisy office, completely cutting off the hum of engines and conversations of colleagues.
- 🔊 Transparency mode: required when crossing the road or talking to the cashier to hear the world around you without removing the headphones.
- 🔇 Off mode: saves battery power when external noises do not interfere, for example, in a quiet room or while sleeping.
It's worth noting that the efficiency of the ANC is directly dependent on the density of the ear canal, and if you see the "Check the landing" recommendation in the app menu, you can't ignore it, because otherwise the system will work incorrectly, creating a "vacuum" or whistle effect, and some models also have a noise reduction level setting, where you can choose between maximum comfort and maximum silence.
Use of the Engineering Menu for Calibration
For advanced users who want to access hidden microphone settings, there is a CIT (Customer Integrated Test) engineering menu, a diagnostic tool built into the firmware that allows hardware components to be tested and calibrated, and is logged in through a set of special code in the Phone app.
To get to the menu, dial the combination ##6484## or ##4636##. In the list you will need to find the item associated with the microphone test (usually called “Main Mic”, “Sub Mic” or “Noise Cancellation Test”), Here you can hear exactly how the phone processes sound in real time, and check the performance of each microphone separately.
⚠️ Note: In the engineering menu, it is strongly recommended not to change parameters whose value you do not know (for example, or sensitivity). Incorrect calibration can lead to the fact that the microphone will work with overload or, conversely, become barely audible even after resetting the settings.
In some firmware versions, you can switch the noise reduction profile through the engineering menu, for example, if the standard algorithm is too aggressive and eats up your voice, you can try to choose a profile with a less filtering degree, but this option is not available on all models and depends on the installed version of Android and the regional binding of the device.
☑️ Checking microphones in CIT
Third-party applications for improving sound
If MIUI is not enough, the market offers a lot of third-party solutions that can take over audio management, often used by bloggers and podcasters who record content directly on a smartphone, and allow for real-time or post-processing noise reduction filters.
One of the most popular solutions is the Dolby On application. It automatically analyzes the recording and applies professional algorithms for noise reduction, volume leveling and echo elimination. Another notable mention is RecForge II, which provides manual equalizer and compressor settings, allowing you to fine-tune the sensitivity of the microphone to specific recording conditions.
For calls via messengers (WhatsApp, Telegram, Viber), standard system settings are often not applied, since these applications use their own codecs. In such cases, help applications-record recorders with the function of recording calls, having built-in filters, or the use of headsets with their own DSP-processor that processes sound before it hits the phone.
| Annex | Type of processing | Difficulty | Best application |
|---|---|---|---|
| Dolby On | Automatic (AI) | Low. | Interview recording, vocals |
| RecForge II | Manual setting | Tall. | Professional registration |
| Lexis Audio Editor | Post-processing | Medium | Cleaning up already finished files |
| Lesser AudioSwitch | Switching inputs | Medium | Forced microphone selection |
Using third-party software gives you flexibility, but can consume more battery resources. In addition, some applications require permanent permissions to access the microphone, which may raise questions for privacy-conscious users. Always check the permissions the program requests when installing.
Features of work in messengers and social networks
The problem of noise cancellation in popular instant messengers deserves special attention, as users often notice that in a normal phone call the sound is clear, and in WhatsApp or Telegram the interlocutor hears everything that is happening around, this is due to the fact that VoIP applications use their own compression and data transfer algorithms, which can conflict with Xiaomi system settings.
The messaging settings themselves rarely provide audio quality options, as they are optimized to work on weak networks. However, Telegram and Discord have hidden experimental functions that sometimes allow improved noise cancellation to be enabled, and may require special versions of clients or tweaks to activate them.
Secret codes for checking the microphone
If you encounter a problem when the messengers do not work the second microphone (noise reduction), try to clear the app cache or reinstall it. Sometimes the conflict occurs after updating the MIUI shell, in which case the reset of network settings or forced switching of the Bluetooth codec to the developer menu helps.
Addressing Sound Quality Issues
Even when properly tuned, there can be situations where noise reduction is not working properly. A common cause is the banal contamination of microphone mesh. In Xiaomi smartphones, the microphone holes are very small and easily clogged with dust, pocket pile or earwax (in the case of headsets). Regular cleaning with a soft brush can work wonders.
Another common problem is protective covers. Some thick or improperly designed covers can block air access to the noise cancellation hole located on the upper or lower end of the body, which causes the system to malfunction, creating a "barrel" or deaf sound effect. Remove the cover and see if the quality of voice transmission changes.
- 🧹 Cleaning: Use a soft toothbrush or sticky tape to clean microphone nets.
- 📱 Case: Make sure the cutouts in the case match the microphone holes on the ends.
- 🔄 Reboot: A banal system restart often resets the hung audio drivers.
⚠️ Warning: Never use sharp objects (needles, pins) to clean microphones.You can damage the membrane or push dirt deeper into the case, leading to irreversible breakage.
If software and cleaning don't work, it may be hardware, because in Xiaomi smartphones, the microphone plumes sometimes go away after falls, or the modules themselves fail, and you'll need to have a diagnostic at a service center, where you'll check the signal level on the board.
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The quality of noise reduction depends on the physical condition of the microphones and their correct location relative to the source of noise.