What's the secret to making noise-canceling microphones sound 'studio-like' even when walking down the street?

micro chống ồn - Ảnh 1. — The guy uses a noise-canceling microphone in his headset to support online meetings outside a coffee shop.

Amidst the noise of wind, traffic, and people talking, the noise-canceling microphone still keeps your voice clear. When you make a call, have an online meeting, or record outdoors, the technology helps your voice stand out, minimizing distracting sounds while maintaining the naturalness of your voice.

The technology inside noise-canceling microphones

Modern noise-canceling microphones use a multi-microphone system, combining a main microphone that focuses on the voice and auxiliary microphones that capture environmental sounds. When sound reaches each microphone, there are differences in phase, intensity, and arrival time. These differences are analyzed by the processor to determine which sound source is human and which is noise.

According to Tuoi Tre Online 's research, beamforming technology plays an important role in focusing the microphone in the direction of the voice . Beamforming uses the principle of controlling the phase and amplitude of signals from multiple microphones to create a "sound beam" directed at the voice source.

From a physical perspective, the microphone will increase sensitivity to sounds from the direction it is intended to pick up and decrease sensitivity to other directions. This makes the human voice stand out, and the surrounding sounds fade away, while still maintaining a natural feel.

Another layer of advanced processing is adaptive filtering . As the environment changes, such as strong wind or a loud fan, the processor continuously measures the signal from the secondary microphone to build a “noise map.”

Adaptive filtering compares this signal to the human voice signal, automatically canceling out the characteristic frequencies or fluctuations of the noise without affecting the voice. This is why noise-canceling microphones still work effectively when you move from outdoors to indoors or through different environments.

In addition, condenser microphones with sensitive membranes also help distinguish the amplitude and oscillation of the human voice from noise. The human voice has a stable amplitude and frequency spectrum (about 300-3400 Hz), while wind, impact or machinery oscillate randomly.

This sensitive microphone combined with beamforming and adaptive filtering allows the voice to be precisely "separated" from background noise.

Helps your voice sound clear and natural in any environment

After the microphone picks up the sound, the digital signal processor (DSP) performs a fine-tuning step. The DSP separates the audio signal into multiple frequency bands and processes each band individually. Sounds that are recognized as noise, such as wind, vibrations, collisions, or complex background noise, are reduced in amplitude. Importantly, the DSP preserves the resonance, rhythm, and nuances of the voice, avoiding distortion or harshness.

A common technique is noise suppression by spectral subtraction, in which the DSP measures the frequency spectrum of the environment and subtracts the non-human components. When combined with beamforming and adaptive filtering, this method helps voices stand out while maintaining naturalness.

To reduce mechanical wind noise, many microphones also have physical wind protection, such as a filter or housing that reduces the air pressure directly acting on the microphone diaphragm. When combined with digital signal processing, this technique eliminates much of the wind noise without distorting the voice.

The entire process, from multi-microphone directional detection, beamforming to focus the signal, adaptive noise reduction filtering, to DSP frequency fine-tuning and wind noise reduction, all takes place in a matter of milliseconds. The result is a voice that stands out clearly and smoothly while the surrounding chaos is almost completely eliminated.

Thanks to the sophisticated combination of these layers of technology, noise-canceling microphones have become indispensable equipment in online meetings, outdoor recordings or voice devices, ensuring that every voice is transmitted accurately and easily heard, no matter how noisy the surrounding environment is.

Tuan Vi

Source: https://tuoitre.vn/bi-mat-nao-khien-micro-chong-on-nghe-nhu-o-phong-thu-du-dang-di-giua-pho-20251114135001719.htm