Why Xiaomi Phones Have Bad Sound When Talking: A Complete Problem

When a person complains of a quiet or intermittent sound while calling Xiaomi, it can come on suddenly and embarrass the user. Often, smartphone owners are faced with speakers who have worked flawlessly for months, begin to wheez, hiss or just become barely audible. This does not always mean that the device breaks down, in most cases the problem lies in software failures or banal pollution.

In this article, we will look at all the possible causes of audio impairment when talking on Xiaomi and Redmi devices, we will look at both the software settings hidden in the depths of the engineering menu and the physical factors that affect the quality of voice transmission. Understanding the nature of the problem is the first step to effectively fix it without visiting the service center.

Sometimes it is enough to simply restart the device to fix the temporary failure of the communication module, but if the problem is systemic, deeper interventions will be required. It is important to consistently check each item to identify the culprit of the bad sound, whether it is a software bug in the shell of MIUI or HyperOS, or physical wear of the dynamic emitter.

Hardware causes and pollution of speakers

The most common reason that the sound in a phone becomes quiet or deaf is the banal pollution. The speaker grid at the top of the screen has microscopic holes that are easily clogged with dust, pocket pile or skin fat, and over time, this layer thickens and creates an acoustic barrier that prevents the sound wave from spreading freely.

If you wear a smartphone without a protective cover or use a poor quality film, the risk of small debris entering the case increases significantly. Even dust that is invisible to the eye can reduce the volume by 30-40%. In addition, the protective glass, glued with a displacement, can block the sound generator, which will distort the sound or create an echo effect for the interlocutor.

• 🧹 Dry cleaning: Use a soft toothbrush to clean the speaker mesh neatly with circular movements.
• 💨 Compressed air: A canister with compressed air will help blow dust from hard-to-reach places without disassembling the body.
• 🧽 Sticky tape: Stationery tape can collect surface dust, but don't use wet wipes to keep water from driving inside.

⚠️ Note: It is strictly forbidden to use sharp objects (needles, pins) to clean the speaker. You can damage the membrane or puncturing the protective mesh, which will lead to an irreversible decrease in the sound quality.

In addition to the contamination, it is worth checking the integrity of the case itself, if the phone recently fell, the plume connecting the main board to the speaker module could move away, in which case the sound may disappear intermittently (periodically) when you press certain areas of the case or when you change the position of the smartphone in your hand.

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Before cleaning, be sure to turn off your phone to avoid accidental calls or short circuits in the event of static electricity hitting.

Software conflicts and MIUI/HyperOS settings

Xiaomi’s shells have many noise reduction and sound enhancement features that sometimes don’t work properly. Algorithms can mistake the voice of the interlocutor for background noise and try to “muffle” it, resulting in a speech interruption effect or a sharp decrease in volume, especially in mid- and low-end models where CPU resources are limited.

Often, problems are caused by a conflict of installed applications. Third-party programs for managing calls, recording conversations or sound "improvers" can intercept control of the audio stream. If the problem occurs after installing new software, try to delete it and check the communication in the "clean" state of the system.

Also, you should pay attention to the modes of operation. Enabling Do Not Disturb or activating specific sound profiles can limit the volume of the call. Check the settings in the Settings → Sound and vibration section. Make sure that the volume sliders are twisted to the maximum for the Call section, not just for multimedia.

Some firmware versions have a codec switching bug. The system can get stuck on a low-quality codec, which significantly worsens speech intelligibility. Resetting to factory settings (after backup) often helps to eliminate configuration software errors that cannot be fixed by a normal reboot.

Problems with network coverage and VoLTE

The quality of the sound during a conversation depends on the technology of voice transmission. If your operator and tariff plan support VoLTE (Voice over LTE), but the function is disabled in the settings, the call can be made over 2G or 3G networks. This leads to a narrow frequency range, making the voice of the interlocutor deaf and indistinct, especially in conditions of poor reception.

Enabling VoLTE allows high-quality voice (HD Voice) to be transmitted in parallel with the Internet. However, if the LTE signal is unstable, the phone can constantly switch between communication standards, causing interruptions and audio artifacts, in such cases it is better to force the network to 3G/2G mode through an engineering menu or standard settings to stabilize the connection.

If you're in a sensitive area, the phone automatically increases the transmitter power, which can cause additional interference in the audio track, and in such situations, the person may hear not only your voice, but also the characteristic crackling or static caused by the interference of the signals.

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Stable but slower 3G often gives better sound in poor coverage than a 4G/LTE download.

Configure the engineering menu and codecs

For advanced users, Xiaomi provides access to an engineering menu where you can fine-tune the microphone and speaker settings, a powerful tool that allows you to increase the sensitivity of the microphone or change the noise reduction profile, but you need to use it with caution so as not to disrupt the radio module.

To get to the menu, open the Phone app and enter the code ##3646633##. After you go to the Hardware Testing section, select the Audio tab. Here you can set up Audio Debug and Speech Enhancement. By changing the settings, you can force higher-quality codecs to be enabled or change the signal amplification level.

⚠️ Warning: Don't change the values of parameters you're not sure about. Incorrectly adjusting frequencies or amplification levels can cause the sound to become too quiet or, conversely, there will be strong distortions and whistles.

In Speech Enhancement, you can select the type of noise reduction. If you have a "Dual Mic NR" value, try switching to "Single Mic NR" or turning off the noise emitter completely for inspection. Sometimes aggressive noise cancellation eats away at some of the voice, making speech robotic.

Mechanical damage and wear of components

Over time, the speaker is a physical device that tends to wear out. The speaker membrane can lose elasticity, and the magnetic system can demagnetize, although the latter is extremely rare. A more common problem is the oxidation of the speaker's contacts due to moisture or high humidity.

If the phone was hit, it could damage not the speaker itself, but the circuit board or connector. In models with a fixed battery and a tightly assembled body, even a microscopic crack in soldering can lead to loss of contact. The symptom of this damage is often that sound only appears after strong pressure on the back cover or top of the smartphone.

• 💧 Moisture: Water intrusion causes contact oxidation and membrane sticking. Ultrasound cleaning is required.
• 🔨 Blows: Can cause cracks in the speaker body, causing rattling at high frequencies.
• 🔥 Overheating: Prolonged heating can warp the adhesive base of the speaker, shifting it relative to the sound generator.

In the case of mechanical damage, software methods are powerless. The only solution is to replace the speaker with a new module, because these miniature components are usually not repairable. The cost of the spare part is usually low, but the work requires skills and tools.

Influence of covers and accessories

Don't discount the impact of external accessories. Some protective covers, especially thick or made of tight rubber, can cover the speaker or microphone opening. Even a slight displacement of the case after falling can create an acoustic stopper.

Also, using non-original or cheap headsets (Bluetooth or wired ones) can create the illusion of bad sound in the phone itself. Always check if the audio stream has switched to the connected device. Sometimes the phone "thinks" that the conversation is going through the headset, and reduces the volume of the main speaker to a minimum.

Check if there's a protective film or glass on the screen that covers the top end. Even millimeter displacement can critically affect the noise reduction system, which uses an extra microphone (usually located on the top end) to cut off external noise. If that microphone is closed, the system starts to malfunction.

Frequent Questions and Answers (FAQ)