How to completely disable noise cancellation on Xiaomi Redmi 9: 4 working methods

Xiaomi Redmi 9 is one of the most popular budget smartphones, but its built-in noise cancellation during calls and recording voice messages often causes users to dissatisfaction. Sound processing algorithms can distort voice, eat up quiet sounds or create a “robotic” effect. If you are faced with the fact that the interlocutor does not hear you well and your voice sounds unnatural, the problem is precisely aggressive noise cancellation.

In this article, we’ll look at all the possible ways to turn off or reduce noise cancellation on the Redmi 9 (including the Redmi 9A/9C/9T models), and explain why the manufacturer doesn’t add a direct switch to the settings. It’s important to understand that completely disabling noise reduction can degrade sound quality in noisy conditions, but it will restore naturalness to the voice in a quiet environment.

Why is the Redmi 9 sound suppression too aggressive?

Xiaomi smartphones use Qualcomm-based noise cancellation software (since the Redmi 9 has a Helio G80/G35 processor from MediaTek, not Snapdragon, the problem is often associated with MIUI firmware).

  • 🔊 Incorrect microphone settings in firmware - by default activated all filters for "purity" of sound.
  • 📱 Updates MIUI, They break the balance between noise reduction and natural voice.
  • 🎤 Hardware Limitations – Budget microphones require strong software processing.
  • 🔧 Hidden Menu options that users accidentally change.

Interestingly, on more expensive Xiaomi models (like the Redmi Note 10 Pro or POCO F3), noise cancellation is softer, due to the use of separate sound processing chips and better microphones. In Redmi 9, the load is placed on software algorithms that do not always cope correctly.

⚠️ Warning: Disabling noise reduction can cause the person in noisy places (streets, transport) to hear background sounds much louder than your voice.

Method 1: Turning off noise reduction through standard MIUI settings

Some versions of MIUI (especially those based on Android 10/11) have hidden options for setting up the microphone. Try this first, it's the safest and doesn't require root rights.

Instructions:

  1. Open the Phone app and dial the combination: ##36446337## (this is the engineering menu for the microphone test).
  2. In the menu that appears, select Microphone.
  3. Scroll down to Noise Suppression and set the Disable value.
  4. Save the settings and restart the smartphone.

If this code doesn’t work, try an alternative:

  1. Go to Settings. → The phone.
  2. Press 5-7 times on the MIUI version to activate the developer mode.
  3. Return to the main settings, open Additional settings → For developers.
  4. Find the USB Debugging and OEM Unlock option – turn them on (this can open access to hidden settings).
  5. Now try to re-enter the engineering menu code.

Backup important data | Check battery power (minimum 50%) | Record current rollback sound settings |Use headphones to check microphone quality-->

If the engineering menu is not available, move on to the next method. In some firmware, Xiaomi blocks access to these settings to "protect the user from himself."

Method 2: Using applications to fine-tune the microphone

If the standard settings don't work, you can use third-party applications that don't turn off noise reduction completely, but they do reduce the noise intensity.

The best apps for Redmi 9:

  • 🎛️ SoundAbout – reassigns sound routes and allows you to disable microphone processing for individual applications (for example, only for WhatsApp).
  • 🔇 Microphone Noise Reduction Disabler - specialized software for disabling noise reduction (requires root rights on some firmware).
  • 📱 MIUI Hidden Settings – reveals hidden options MIUI, including microphone settings.

Instructions for SoundAbout:

  1. Download the app from Google Play and open it.
  2. Go to the Media Audio section.
  3. Select Phone Call and install Use wired headset mic, even if the headset is not connected.
  4. Save the settings and check the sound quality.

⚠️ Note: Apps like Microphone Noise Reduction Disabler may conflict with system processes MIUI. If after installation, the smartphone began to brake or overheat - delete the program and restart the device.

Standard call.|WhatsApp|Telegram|Viber|Other-->

Method 3: Editing system files (for advanced users)

This method requires root rights and is designed for power users, and we do not recommend it for beginners, since incorrect changes can lead to complete loss of sound or a “brick” of the microphone.

If you are willing to take a risk, follow the instructions:

  1. Get root rights with Magisk (the instructions for Redmi 9 are available on the 4PDA forum).
  2. Install a file manager with root support (such as Root Explorer or FX File Explorer).
  3. Go to /system/vendor/etc/.
  4. Find the file. audio_effects.conf or mixer_paths.xml (depending on the firmware version).
  5. Open the file in the text editor and find the lines with mention noise_suppression or ns.
  6. Replace the true with false and set the noise reduction level to 0.
  7. Save the file, set the rights to 644 (r-w-r--r---) and restart the smartphone.
File.ParameterReference valueNew meaning
audio_effects.confnoise_suppressiontruefalse
mixer_paths.xmlns_level3 or 40
audio_policy.confaec_enabled10

If after the changes, the microphone stopped working completely, restore the original values of the files or reflash the smartphone.

What if the sound is lost after editing the files?
If the microphone stopped working, try: 1. Return the original values in the edited files. 2. Delete the cache of the Phone application and Settings in Settings → Appendices. 3. Reset network settings to Settings → SIM-maps and mobile networks → Reset network settings. 4. If nothing helps – reflash your smartphone via Fastboot or Recovery.

Method 4: Flashing on custom firmware (radical solution)

If all the previous methods didn't work, the most radical way is to install custom firmware, where noise cancellation is disabled by default or can be configured flexibly. Redmi 9 is suitable for:

  • 📱 LineageOS – “clean” Android without unnecessary sound handlers.
  • 🔧 Pixel Experience – firmware with audio settings like on Google Pixel.
  • ⚡ Havoc-OS - customizable firmware with a separate menu for the microphone.

Installation instructions:

  1. Unlock the bootloader through the official Xiaomi website (can take up to 7 days).
  2. Install custom recovery (TWRP or OrangeFox).
  3. Download firmware and GApps (if you need Google services) from the 4PDA or XDA-Developers website.
  4. Reboot to recovery, make a full wipe (Dalvik, Cache, System, Data).
  5. Install firmware and GApps, then restart.

After installing custom firmware, noise cancellation can be turned off in the Settings → Sound → Sound Effects menu or through the AudioFX application (part of many custom firmware).

⚠️ Attention: Installing custom firmware will void the warranty on Redmi 9 and may result in data loss.Be sure to back up through the Redmi 9 before the procedure TWRP or MIUI Backup.

How do you check that the noise reduction is actually turned off?

To make sure the changes work, follow the following steps:

  1. Record a voice message on WhatsApp or Telegram in a quiet room. Compare it to a recording before the changes - a natural voice without metal aspirations means that the noise cancellation is turned off.
  2. Call another phone and ask the person to rate the sound quality, and notice the background noises, if they're overly audible, the filtering is really weakened.
  3. Use the Spectroid app (sound spectrum analyzer) – with active noise cancellation, “failures” in low and high frequencies will be visible on the chart.

If the sound quality deteriorated after the noise cancellation was turned off (echoes appeared, the interlocutor hears himself with a strange delay), then the AEC (Acoustic Echo Cancellation) also turned off along with the filtering, in which case you will have to find a balance between the purity of the sound and its naturalness.

💡

Turning off noise cancellation doesn't always improve sound quality; in noisy environments (street, traffic), it's better to leave it on, and in quiet environments, experiment with settings.

Frequent Mistakes and How to Avoid Them

When you try to turn off noise cancellation, users often face typical problems, and here are the most common ones and how to solve them:

  • 🔄 After the reboot, the settings are reset, which means that the changes have been made to temporary files. /system Or use Magisk modules.
  • 🔇 The microphone stopped working completely - most likely, you turned off not only noise cancellation, but also other critical parameters (for example, you turned off the noise reduction, aec_enabled). Return the original values.
  • 📱 Configuration apps don’t work – check if they block them MIUI Optimizations (turn off in the developer settings).
  • 🔊 The sound has become too quiet - noise cancellation often works with a microphone amplifier.Try to turn up the microphone volume in the engineering menu (#36446337##).

If you are not sure about your actions, it is better to seek help from the profile forums (4PDA, XDA-Developers) or the specialists of the service center. Remember: incorrect changes in system files can lead to a “brick”** (complete inoperability) of the smartphone.

💡

Before any manipulation of system files, create a backup via TWRP or the built-in MIUI Backup application. This will quickly restore the smartphone to work in case of an error.

Can noise cancellation be turned off only for a specific application (like WhatsApp)?
Yes, using the SoundAbout app (method 2). In the settings, select Per-app settings and set Use wired headset mic for the desired application - this bypasses system noise cancellation.
Why did the noise reduction switch on again after the MIUI update?
Updates MIUI To avoid this, use Magisk modules to block updates to specific configuration files (for example, use Magisk modules to block updates to specific configuration files, audio_effects.conf).
Will the noise reduction switch on the Redmi 9A/9C work?
Yes, all of the methods described above apply to these models as well, as they are built on the same MediaTek Helio G platform and use similar firmware. MIUI. Exception - custom firmware: for Redmi 9A their choices are limited.
Can noise reduction be turned off without root rights?
Yes, but not completely. With standard settings (method 1) or applications like SoundAbout (method 2), you can weaken the filtering, but you need root rights or custom firmware to completely shut down.
How to get the noise reduction back if the sound quality is getting worse?
If you've edited system files, return the original values. If you've used the engineering menu, open it again and turn on Noise Suppression. For custom firmware, check the settings in the Sound → Effects menu.