High Performance ANC AEC Microphone 2 MIC Array Solution

Declaration

This microphone and micrphone array solution is copyrighted by Shenzhen Shiningintl Technology Co., Ltd. Without permission, no unit or individual may reproduce, disseminate, transcribe, or preserve this publication in electronic, mechanical, magnetic, optical, chemical, manual form, or translate it into other language versions. Once found, legal responsibility will be pursued. Smochm is the brand owned by Shenzhen Shiningintl Technology Co., Ltd. In the article the Shiningintl is equal to Smochm.

Shenzhen Shiningintl Technology Co., Ltd. guarantees the accuracy and reliability of the information provided in this manual but is not responsible for any textual errors or omissions that may occur. Shenzhen Shiningintl Technology Co., Ltd. reserves the right to change this manual, and any modifications will not be announced. Please contact us at the time of ordering to obtain the latest product information. The company is not responsible for any user’s infringement of third-party copyright or other rights when using our products.

1.What is high performance ANC AEC microphone MIC ?

Microphone plays a very important role in the system as a voice input device, in order to pick up the sound clearly and get better voice fidelity, here is the system block diagram for a high performance micrphone system.

MIC Sensor: pick up the audio signal around

Echo pickup: to get Echo signal from the speaker, then the microphone DSP can use the algorithm to remove it.

DSP: run the algorithms to deal with signals from MIC sensor and ECHO pickup circuit.

The SMOCHM MICROPHONE SERIES module by Shiningintl company is an intelligent, low-power micphone module with powerful dual core deep-learning DSP processor inside, this module has a build-in neural network and an efficient inference engine.

It utilizes advanced noise reduction technology to achieve far-field pickup over a 10-meter distance. This product accumulated Shiningintl long term experience in audio research, finely we tuned to this high performance module , integrated multiple algorithms including Acoustic Echo Cancellation (AEC), Noise Cancellation (ANC), Automatic Gain Control (AGC), Deep Neural Networks (DNN), Acoustic Echo Suppression (AES), and Automatic Speech Recognition (ASR) into a comprehensive front-end voice solution.

Shiningintl high end microphone series module is compatible with many systems, such as windows, Linux, Android ，work perfectly in major video conferencing systems, large screen all-in-one video systems,Zoom， Skype, QQ, and other video or voice communication systems, with shiningintl microphone module, the user can create its products in fast speed, shorts its time to market.

Normally there are three microphone categories in smochm solution:

Omnidirectional near field Series A:

near field Microphone modules, this series microphone module are using in near distance sound pick up, normally the distance is 1-5 meters,

omnidirectional far field Series B:

Far field Microphone modules, Series B microphone module has better performance, the working radius can be 8-10 meters

Directional Series C:

directional microphone, with our series C microphone modules, it only pick the audio signal within certain angle of the MIC sensors,

2.the smochm high end microphone module features

• Pickup voice in Far-field distance
• Supports dual (or single) microphone linear array, built-in far-field recognition and noise reduction technology, enabling a pickup distance of up to 10 meters
• Acoustic Echo Cancellation
• Utilizes the spatial filtering characteristics of the microphone array to form a directional pickup beam and suppress noise outside the beam, ensuring high quality voice recording
• Reverberation Removal
• Reverberation removal method based on Multi-Channel Linear Predictive (MCLP) algorithm, directly initializing the target signal covariance with the array collected signal to further enhance speech dereverberation performance
• No Calibration Needed
• Plug and play , no driver required, supports operating systems such as WINDOWS and Android

3.system architecture of smochm high performance microphone module solution

3.1 the theory of AEC(acoustic echo cancellation)

When speaker outputting and recording occur at the same time, the sound from the speakers will also recording by the microphone simultaneously, the sound from the speaker will be picked up by the microphone, then creating an echo that affects the quality of the recording. In order to reduce the interference , Shiningintl introducing a reference signal from the speaker signaland applying filtering calculations to the recording signal, it is possible to eliminate the impact of the device’s own playback on voice interaction, improve the signal-to-noise ratio, and achieve real-time voice interaction and interruption.。

3.2 Connection block

As shown in the figure, the module take an external sound signal and echo reference signal from the speaker as input,
After the echo cancellation and active noise cancellation, the digital audio signal is go through the USB port to the system using UVA protocol

4.components for smochm high end microphone module

4.1 shiningintl high performance microphone SERIES main motherboad

4.2 2 MIC input(there are waterproof and no-waterproof models, the default length is 15cm)

4.3USB connection wire(the default length is 1.5 meters, the connect size is 1.25×4 )

4.4 AEC Echo cancellation signal line

5.installation requirement

5.1There are mounting holes on the shiningintl HIGH PERFORMANCE MICROPHONE SOLUTION motherboard, please pay attention to avoid high temperature, humidity, dust and other environments during installation;

5.2 The MIC pickup sensor is a voice input source, so the installation requirements for the MIC sensors are relatively high, and the customer should pay attention to it when designing the installation structure of this part, otherwise it may not achieve a good voice input effect;；

5.3 The sound path from the sound source to the microphone is as short and wide as possible. For the close-fitting shell installation, as shown in Figure 1, the depth of the acoustic hole (the distance from the outside of the shell inlet hole to the outside of the MIC inlet hole) is required to be less than 1.5mm, and the diameter of the acoustic hole is as large as possible (minimum 2mm), and it is best if the microphone can be directly on the surface, as shown in Figure 2;

5.4 There should be no cavity in the sound path, and there should be no gap between the Microphone and case surface and the installation method as shown in Figure 3 is not allowed.

5.5 The MIC sensors should be kept away from interference or vibration (horn vibration, structure rotation vibration). For vibration, the silica gel case is generally used on the side of the MIC sensor for shock absorption and sealing treatment, and the softness and hardness of the silicone case can be adjusted according to the actual structural form, and it is generally required to be as soft as possible;

5.6 the structural design for the speakers should avoid the distortion caused by the structure, and the speaker should be shock-proofed design and installation, because the speakers vibration may affect the MIC sensor

5.7 To avoid sound propagation inside the case, that is, the sound of the speaker can not reach the MIC sensor in the inner space of the case, it can only be transmitted to the microphone through the air outside the case, it is recommended that the speaker and the microphone are placed in separated different space or seals the microphone back end with good performance sealing glue . as shown in figure 4

5.8 For electret microphones, the protection of the microphone should be considered in the case design , the MIC installation extrusion may cause sound distortion.

5.9 The microphones are strictly independent from each other, and the sound pickup hole of each microphone is its only sound inlet hole (one method to verify: press and cover the voice pickup hole of the microphone with your finger, if the pickup volume from this MIC reduces more than 10dB, it is ok.);

5.10 The microphone needs to be isolated from the hole by a rubber case to reduce the vibration and sound transmission of the instruction,

5.11 According to different application scenarios, covers may need to put on the surface of the MIC sensors, such as windproof cotton in windy environment (similar to the scene that the car air conditioner directly blowing to the MIC sensor) and dustproof cotton can be added to the surface of the MIC sensor.

6.Applications with smochm microphone solution

This high performance microphone modules are widely used in terminal equipment such as finance, medical care, taxation, smart TV, conference screen, pickup, etc.

7.Parameters