How to turn on noise cancellation on Xiaomi Redmi Note 8

Modern smartphones like the Xiaomi Redmi Note 8 are equipped with advanced sound processing algorithms that are designed to ensure crystal clear sound during conversations. However, many users do not even realize that their device has a powerful toolkit to suppress background noise. Owners often face a situation when people complain about the hum of the wind or foreign sounds, although the hardware of the phone is quite capable of doing this. The problem lies in the software settings that by default may be hidden or not optimally tuned for specific operating conditions.

In this article, we will take a look at all the ways you can activate and fine-tune your noise reduction systems using a Qualcomm processor installed on your device, and learn not just to include standard functions, but also to use hidden engineering menus to further calibrate your microphones. Understanding how audio codecs work will allow you to significantly improve communication in noisy places, such as a high-traffic street or crowded public transport. It is important to approach this issue in a comprehensive manner, taking into account both the software and physical aspects of the operation of the sound subsystem.

It’s worth noting that the MIUI algorithms that make up Redmi’s shell change periodically with updates, and the location of some switches may vary. However, the basic principles of how the audio subsystem works remain the same for the entire Snapdragon line of smartphones. We’ll look at both the standard Android operating system tools and Xiaomi-specific utilities. Prepare for some settings to require attention, but the result is worth it.

Hardware features of the Redmi Note 8 audio system

Before you get to software settings, you need to understand the physical basis of sound processing in your smartphone. Redmi Note 8 has two main microphones: one located at the bottom of the case next to the charging connector, and the second on the top end of the device. It is this dual configuration that allows you to implement active noise reduction technologies, cutting off the background hum and leaving the user's voice priority.

The digital signal processor (DSP) built into the Snapdragon 665 chipset takes the main load of real-time sound filtering. It analyzes the phase and amplitude differences of sound waves hitting different microphones and mathematically subtracts the noise from the pay signal. The effectiveness of this process depends on the correct operation of software drivers and the absence of physical obstacles in the form of dirt or covers covering the holes. It is critical that the bottom microphone hole is not blocked dust or a poorly designed case, as this is the primary input voice.

⚠️ Attention: The use of tight protective glasses or covers with protruding sides can physically block the access of sound to the upper microphone, which completely disavows the operation of the noise reduction system, since the algorithm will cease to receive data about the surrounding noise.

The quality of the recording also depends on the state of the membranes of the dynamic conversational speaker, which, when playing the sound of the interlocutor, can also create resonant vibrations that are captured by the microphones. In some cases, users confuse problems with the speaker (wheezing, quiet sound) with problems of noise cancellation. If you hear yourself in a tube with an echo or delay, this can indicate a failure in the feedback circuit, where the sound from the speaker again enters the microphone and amplifies.

Basic sound setting through the system menu

The first step to improving communication quality is to check the standard settings that are available to each user without the need to obtain root rights. MIUI There is a basic section for sound effects, although it is often focused on multimedia rather than phone calls. However, activating certain profiles can affect the overall sensibility of microphones. Go to Settings → Sound and vibration → Sound effects to familiarize yourself with the available options.

Here you can find the MI Sound Enhancer switch, which, despite the name, affects voice processing in some use cases. Experimenting with this setting can help you find a balance where voice becomes clearer and the background hum decreases. However, to directly customize phone calls, you need to consult the phone or Contacts menu itself, where additional recording and playback options may be hidden.

• 📱 Open the Security app and find the audio optimization section if it is available in your firmware version.
• 🎚️ Check the equalizer settings and try to lower the frequencies in the range 100-300 Hz, where the low-frequency hum is often concentrated.
• 🔇 Make sure that Noise Suppression is not disabled in the settings of a particular call app (for example, Viber or WhatsApp have their own internal settings).

Do not ignore the volume settings. Sometimes automatic volume control in noisy environments works incorrectly, trying to compensate for the noise with voice amplification, which leads to distortion. In the Settings menu → Sound and vibration → In addition, you can find options related to the behavior of the device when you connect the headset or in hands-free mode. The correct configuration of these parameters is the key to the stable operation of the audio tract.

Using an engineering menu to calibrate microphones

For a deeper setup that is hidden from the average user, there is a so-called engineering menu, which is a powerful tool for diagnosing and configuring hardware components of Xiaomi smartphone, accessed through a set of special code in the Phone app. Enter the code ##6484## or ##4636### to get into the test menu, and here you can check the performance of each microphone separately.

In the hardware testing section (often referred to as CIT - Customer Interactive Testing), select the item associated with the Main Mic (main microphone) and Sub Mic (secondary microphone). After the test, you can see the signal level in decibels. If one of the microphones shows significantly lower values or complete silence during active conversation, the problem may be hardware, and the software noise cancellation will not work, since it has nothing to compare the signal with.

Codes for accessing testing:




1. ##6484## - Basic Engineering Menu (CIT)




2. ##4636### - Phone Information Menu




3. ##3646633## - MediaTek Engineering Menu (not for Redmi Note 8, but good to know)

In some firmware versions, you can reset the audio codec to factory settings through the engineering menu, which helps if the sound gets worse after the firmware update. Find the Audio Calibration or Reset Audio Settings option. This procedure will overwrite the DSP configuration files, eliminating possible software errors accumulated during operation. This is especially true if you have previously installed various audio mods or patches.

⚠️ Warning: Do not change the Gain or other parameters in the engineering menu if you are not sure of their purpose.Too high gain of the microphone can cause severe distortion, whistles and even damage to the speaker due to overload.

Third-party applications to improve call quality

If there is not enough regular funding, Google Play apps come to the rescue, which can intercept audio streams and process them with their own algorithms, and one popular solution is to use noise-canceling applications that simultaneously improve both incoming and outgoing signals, such as Call Recorder with built-in filters or specialized audio utilities.

There are also applications that work as system equalizers with real-time noise reduction, requiring special permissions, often through ADB or root rights, but can work wonders. For example, the Lesser AudioSwitch app allows you to force switching of sound sources and microphones, which can help if the system mistakenly selects the wrong microphone in a particular situation (for example, when using a headset).

• 🎙️ Krisp (or mobile analogues) – uses AI to remove noise, but may require use in specific applications for calls.
• 🔊 Volume Control Plus – allows you to fine-tune the amplification levels for different use cases.
• 🛠️ Google’s Sound Amplifier is an officially supported app that can amplify quiet sounds and suppress loud noise.

It is important to understand that using third-party applications that interfere with the audio stream can increase latency. This may be imperceptible in conversation, but when video or in games, the delay will become noticeable. In addition, such applications can consume additional battery power, as the processor will be constantly busy processing audio data.

Physical Factors and Device Maintenance

No software tweaks can help if the microphones are physically contaminated. In the process of operating, dust, pocket pile and skin fat inevitably enter the holes of the Redmi Note 8 microphones, creating an acoustic cork that silences sound and disrupts the noise-cancellation algorithms as the microphones begin to receive a distorted signal. Regular cleaning is a basic requirement for quality communication.

Use a soft brush or a special velcro to clean. It is strongly recommended not to use sharp objects such as needles or toothpicks, as you can damage the protective mesh or the membrane of the microphone itself, which will lead to irreversible consequences.

Pay attention to protective covers. Cheap siline cases can become deformed over time and fit tightly into the microphone holes, especially if they don't have accurate cutouts. Remove the case and check the quality of the connection without it. If the problem has disappeared, then it's the accessory, and it should be replaced with a better one, with the right cutouts or raised sides.

Setting up Bluetooth headsets and headphones

If you use wireless headphones with Redmi Note 8, the noise reduction setting is different, and it's important to distinguish between active noise cancellation (ANC) in the headphones themselves and microphone noise cancellation when talking, the first being the physical buttons or sensors on the headphones, and the second is the Bluetooth profile and smartphone settings.

In Bluetooth settings on your phone, find the connected device and tap the gear next to it. Make sure Hands-Free and Audio profiles are activated. In some cases, turning off the Absolute Volume option, which can conflict with headset volume control, helps. Also check if Mono-audio mode is on, which sometimes impairs spatial perception and noise sound sound sound sound sound sound sound sounders.

For Xiaomi headphone owners (AirDots, Mi True Wireless), there is a Mi Earbuds app or settings in MIUI that allows you to update the firmware itself. The firmware update often includes improvements to the microphone and noise reduction algorithms. Watch out for notifications about new versions of the software for your accessories, as this is a direct way to improve communication quality.

Solving Common Sound Problems

Even after all the settings, there can be specific problems, like people hearing their own echoes, which is a classic sign that the sound from the speaker is hitting the microphone, try to turn down the speaker while you're talking, or use the headset, and if the echo remains, the bottom microphone may have malfunctioned, and the phone automatically switched to the top one, which is closer to the speaker.

Another common problem is the robotic voice, which often happens when the network signal is bad, when the codecs compress the sound too aggressively, or when the software filters conflict. → SIM-maps and mobile networks → Type of network (c) 5G/4G on 3G If the quality has improved, the problem is the carrier's coverage, not the phone.

⚠️ Attention: If after resetting and cleaning the microphones, the problem with the sound quality persists, and the engineering menu shows the absence of a signal from one of the microphones, hardware failure of the plume or the microphone itself is likely.

Remember, the quality of communication depends on the operator. In areas of insecure reception, phones automatically increase the sensitivity of microphones, which increases background noise. In such situations, even the best noise reduction algorithm may not cope with the physics of radio wave propagation. Using Wi-Fi Calling (if supported by the operator) often solves quality problems indoors.

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Try to turn on In-Flight mode for 10 seconds and then turn it off. This will force the phone to re-register online and may assign you to a less busy base station, which will improve the quality of the communication channel.

Final operational recommendations

To sum up, switching on and adjusting noise reduction on the Xiaomi Redmi Note 8 is a process that requires a comprehensive approach. There is no one magic button that will solve all problems instantly. You need to combine proper physical operation (cleanliness), competent basic system setup and, if necessary, the use of advanced calibration tools.

Check for MIUI system updates regularly. Xiaomi engineers are constantly working to improve sound processing algorithms, and new firmware versions may contain important patches for the audio codec. Ignoring updates can leave you with known bugs that have already been patched by developers.

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The most effective way to combat noise is to combine clean microphones, the current firmware version, and the correct position of the phone during a conversation (microphone to voice source).

They are designed to suppress constant background noise like traffic or fan hum, but sudden loud sounds or wind gusts are harder to filter completely. Understanding these limitations helps in setting realistic expectations and finding practical workarounds, such as moving to a quieter location for important calls.