Many Xiaomi, Redmi and POCO smartphone owners, when they look at the settings menu in detail, encounter a strange item called “DTMF signals” or “DTMF sound.” This parameter often puzzles users who are not familiar with telecommunications standards. At first glance, it seems that this is some complex technical feature that affects the quality of communication, but in fact it is much simpler.
In this article, we will explore what is behind this acronym, why it is needed in 2026, and why the sound of buttons can be annoying or useful. We will not only cover the theoretical part, but also give specific instructions for managing this function in the shells of MIUI and HyperOS.
Understanding the tone set will help you not only customize your phone, but also better navigate the menu of service codes and automatic secretaries. Let's take a look at how this standard works in modern devices.
What is DTMF and its principle of operation?
DTMF (Dual-Tone Multi-Frequency) is a telecommunications standard that is used to transmit numbers and symbols over the telephone network. When you press a button in the Phone app, your smartphone generates a specific sound consisting of two sine wavelengths of different frequency.
Each button on the digital keyboard (0 to 9, and * and #) has its own unique frequency pair. For example, when you press one, the frequencies of 697 Hz and 1209 Hz are transmitted (IVR-Bank systems, auto secretaries, they can hear these frequencies and they can understand which number you've chosen, and they can navigate the press 1 menu without human intervention.
It is important to understand that in modern smartphones, including Xiaomi Mi 14 or Redmi Note 13, the data transfer process often occurs digitally, but the visual and audio imitation of the tone set is saved for feedback from the user.
Why you need DTMF sound in your smartphone
The main function of these signals is to provide feedback, and when you dial, the sound confirms your every action, without it, it would be difficult to know whether the vibration is triggered or the screen responds to touch, especially in noisy environments, and the tone is necessary for working with automated services.
If you call a bank, a service provider, or order pizza via an answering machine, you can do it. DTMF-signals allow the system to understand your choices. If the phone's settings turn off the transmission of these signals (or their sound), the automation may simply not "hear" your input, and the connection will not be switched to the desired department.
However, many users are annoyed by the loud squeak of dialing, especially if they are used to quiet dialing or are in a quiet place. Xiaomi smartphones have the ability to flexibly adjust this behavior, separating the sound of the interface and the sound of the signal transmission to the network.
Where to find DTMF settings in MIUI and HyperOS
The interface of the MIUI shell and the new HyperOS may differ depending on the Android version and the firmware region, but the search logic remains the same. Often users search for this item in the general audio settings, which is an error. Tonal dial management is directly in the Phone app.
To get to the menu you need to open the standard “calling” and go to the settings. There, in the “Additional” or “Settings of the set”, you can find the switch responsible for touch sounds or DTMF. In some versions of the firmware, this option can be hidden in the deep menu “Extended settings”.
If you can't find the right item, search the system settings. Type "DTMF" or "tonal" and the system will suggest you move to the desired section. This is true for Xiaomi 13T models and later, where menus are often reorganized.
Instructions for signal switching on and off
The process of controlling the sound of the buttons is quite simple, but it requires care, since MIUI has two types of settings: the interface sound (click on the screen) and the DTMF sound (network signal). To completely remove the sound, you need to act consistently.
Open the Phone app first. In the upper right corner, click on the three-dot icon or gear to open the menu. Select Settings. Next, look for the Additional (or Advanced Settings) section. This is where the keyboard Sound or DTMF signals are located.
If you need the buttons to beep when pressed but not transmitting a signal (which is rare), or vice versa, experiment with these settings. For complete (silence), also check the general system settings: Settings → Sound and vibration → Other sounds. There may be duplicated the item "Dial Sound".
| Action. | The way is on the menu | The result |
|---|---|---|
| Turn off the buttons | Phone → Settings → Additional → Keyboard sound | The buttons do not beep when pressed |
| Turn off the interface sound | Settings → Sound and vibration → Other sounds | Clicks disappear throughout the system. |
| DTMF verification | Number #0# (Engineering Menu) | Dynamics and frequency test |
DTMF Sound Problems and Their Solutions
Sometimes users are faced with a situation where the sound of DTMF is not working correctly: it is too quiet, intermittent or absent even when on, this may be due to a conflict of software settings or the peculiarities of the audio codec in a particular module Xiaomi.
A common problem is that the speaker has sound, but the person or the car secretary doesn't "hear" the digits. It's not always a volume problem. There may have been a tone coding failure in the VoLTE or HD-voice settings. Try temporarily disabling VoLTE in the settings. SIM-Check the map and see if a signal is coming.
It’s also worth checking if you have a third-party call app (like Google Phone or Truecaller) that may have their own audio settings that override MIUI system settings, so you need to adjust DTMF inside the third-party app itself.
⚠️ Warning: If your automatic system is no longer responsive to your taps when you make a bank call, don't rush to reset your settings. Try just to pause before entering a number or hold the button longer than usual - sometimes network delay requires a longer delay DTMF-signal.
Using DTMF in Automation and Scenarios
For advanced users using automation (e.g., via Tasker or Xiaomi embedded scripts), DTMF-The signals can be part of complex chains of action, such as a phone that can automatically dial an extra number after connecting to an office.
In a standard Xiaomi phone, you use a pause symbol to do this. When dialing, press the *, +# button (usually in the corner of the keyboard) and select "Pause" (comacus) or "Wait" (comault point), which will form a command that will send the tone automatically after the beep.
This is especially useful for calling offices, where you need to listen to a long greeting before entering an additional number. DTMF-protocol.
Example of a number with pause: +79990000,123
(where the comma is a pause of 2 seconds and the 123 is the extra number)