Badly audible interlocutor on the phone on Xiaomi Redmi Note 9: causes and solutions

You're making an important call, but you can barely hear the person you're talking to, and their voice is interrupted or sounds like a barrel? Bad hearing when calling Xiaomi Redmi Note 9 is one of the most common complaints users have. Some cases are software failures, others are hardware malfunctions. But before you bring your phone to the service center, it's worth checking a few key points.

This article will help you understand why the sound in the tube disappeared or became quiet, and will give step-by-step instructions for diagnosing and fixing the problem. We will look at both simple solutions (for example, cleaning the speaker) and more complex ones (flashing, changing the microphone). We will pay special attention to the unique “jobs” of firmware MIUI Redmi Note 9, which often causes poor hearing.

If after all the manipulations the problem remains - at the end of the article you will find a checklist for contacting the service and tips on how to save on repairs.

1. Checking basic sound settings

Start with the obvious: it may not be the phone that is the problem, but the volume settings or accessories. The Redmi Note 9 has separate controls for media sound and volume of conversation — easy to confuse.

How to check:

• 🔊 Press volume buttons on the sidebar during the call – make sure the slider is not at a minimum.
• 🎧 If you use a headset (wired or Bluetooth), turn it off and check the sound through the phone speaker.
• 🔄 Restart your phone – sometimes crashes MIUI reset.

Also, look at Settings → Sound and Vibration → Loudness and make sure the Call Volume slider isn’t knocked down. If it’s gray and inactive, it’s a sign of a software failure (solution below).

⚠️ Note: On some versions MIUI There's a bug for the Redmi Note 9 when, after you plug in a Bluetooth headset, the volume of the conversation is dropped to 30.

2. Cleaning the speaker and microphone from dirt

One of the most common causes of hearing loss is contamination of a speaker or microphone. On the Redmi Note 9, the speaker is located at the top of the phone (near the front camera), and the microphone is located at the bottom, near the USB-C connector. Dust, hair or moisture can block the sound.

How to clean:

• 🧹 Use a soft toothbrush (dry!) or a wooden toothpick to gently remove dirt from the speaker grille.
• 💨 With compressed air (a cleaning tank), blow through the microphone and speaker holes. Keep the balloon vertically so as not to freeze the components!
• 🚫 Do not use metal objects – they can damage the speaker grid.

If the phone falls in water or has been in the rain, the problem can be more serious, and this requires disassembly and drying of the board, which is not recommended for you to do.

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Before cleaning the speaker, turn off the phone and take out SIM-This will prevent the contacts from accidentally closing.

3. Diagnostics of MIUI software failures

Xiaomi Redmi Note 9 runs on MIUI firmware, which is known for its "surprises." Sometimes after updating or installing third-party apps, the sound during calls disappears or becomes quiet.

Step 1. Resetting the sound settings

Go to Settings → System and device → Settings Reset → Resetting audio settings. This will return all volume sliders to factory values.

Step 2: Checking Application Rights

Some applications (such as call managers or conversation recordings) can block sound. Go to Settings → Apps → Permissions → Microphone and turn off access for suspicious programs.

Step 3: Test in safe mode

If the problem disappears in Safe Mode (starts by holding the power button), one of the installed applications is to blame.

4. Update or roll back firmware

If the problem occurred after the MIUI update, a bug in the new firmware version may be to blame.The Redmi Note 9 is especially sensitive to updates due to the features of the iron platform (Meditek Helio G85 processor).

How to update (if a new version is available):

1. Go to Settings → About the phone → System update.
2. Click on “Check Updates” and install the latest version of MIUI.
3. After the update, reset the sound settings (see the previous section).

How to Reverse the Old Firmware:

If the problem occurs after the update, you can return the previous version of MIUI.

• 📥 Download the necessary firmware from the official Xiaomi website (choose the version for Redmi Note 9, encoding merlin).
• 🔧 Use the Mi Flash Tool to Fastboot Firmware.

⚠️ Attention: Firmware rollback erases all data from the phone! pre-backup through Settings → Additionally. → Backup and reset.

5. check network settings and SIM-map

Poor hearing may not be due to the phone, but to an unstable network signal or problems. SIM-Two problems are particularly relevant on the Redmi Note 9:

• 📶 Weak signal. 4G — phone-to-phone 3G/2G, where the quality of communication is worse.
• 🔄 Conflict of the two SIM-If you use Dual-SIM, one card can jam the other card signal.

How to check:

1. Go to Settings. → SIM-maps and mobile networks.
2. Make sure that 4G mode is enabled (not 3G only or 2G only).
3. If you use two SIM-Check the cards, try leaving only one and check the quality of the connection.
4. Call someone else. SIM-Cards or phone – if the problem persists, it is the operator’s fault.

It is also worth checking whether the “Saving Traffic” mode is activated in the settings. SIM-Cards – It can limit the quality of communication.

Signal level checked (antenna in status bar)

4G/VoLTE mode enabled

Try one. SIM-Card (if Dual-SIM)

Call test from another phone (problem of the operator?)

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6. Hardware malfunctions: when without service can not do

If all the software methods have been tried and the sound is still bad, the problem is probably hardware.

• 🔊 The speaker is responsible for the sound in the tube, and when the voice of the interlocutor breaks, it becomes quiet or disappears completely.
• 🎤 Microphone – if the person you are talking to can’t hear you and you can hear them normally.
• 📶 The antenna module is responsible for receiving the signal. When damaged, communication is interrupted, the voice breaks».
• 🔌 Dynamic/microphone plume – oxidation or break of contacts.

How to diagnose:

Turn on the phone to record the conversation (if any) or use another device to record your voice during the call. If the recording is clear and the person is not hearing you well, the microphone is a problem. If you can't hear the person but the recording is normal, the speaker is to blame.

Cost of repair (example prices for Russia, 2026):

⚠️ Note: If the phone was in high humidity (e.g., in the bathroom while showering), the fault may be due to oxidation of the contacts. In this case, a simple replacement speaker will not help - a full diagnosis of the board is required.

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Before contacting the service, make a backup copy of the data - some malfunctions require a complete reset or replacement of the motherboard.

7. Alternative solutions: what to do if repair is not an option

If repairs are too expensive or the phone is already outdated, you can try to get around the problem with sound in alternative ways:

1.Use of the headset

Wired or Bluetooth headphones with a microphone will completely replace the regular speaker and microphone of the phone, the main thing is to choose models with noise cancellation (for example, Xiaomi Mi True Wireless Earbuds or Redmi AirDots).

2. Sound amplification applications

Google Play has utilities that increase the volume of conversation beyond the standard MIUI limits.

• Sound Amplifier (from Google) – amplifies the sound in headphones.
• Volume Booster – Increases the volume of the speaker (caution, can cause distortion!).

3. Calls through messengers

If the problem is only with mobile, go to calls via WhatsApp, Telegram or Viber. the quality of communication there is often better than that of carriers.

4.External microphone

For important calls, you can connect an external microphone via a USB-C adapter (for example, BOYA BY-M1). This is true if the interlocutor does not hear you, but you hear him normally.

Frequent Questions (FAQ)