In daily life, sound is everywhere, from the roar of machines on construction sites to the honking of car horns on the streets, from the noise of shopping mall broadcasts to campus broadcasts. Noise is constantly affecting people's quality of life. With the increasing demand for ecological environment quality, how to effectively control and reduce noise pollution has become an important issue in our daily lives.

　　1、 Case background

The Fourth Kindergarten of Weiyuan County, Dingxi City, Gansu Province is located on Xinjie Road in Weiyuan County, with a compact surrounding environment. It is adjacent to the county government office building on the west side and the Yixie Garden community on the east side. Every time the kindergarten starts daily playground activities, the original omnidirectional broadcast sound directly affects the daily life of adjacent buildings' offices and residential areas.

To solve the problem of noise in kindergarten playgrounds, the Fourth Kindergarten of Weiyuan County conducted multiple comparisons and professional evaluations, and finally selected a clear and quiet acoustic playground system (campus directional sound system) to solve the problem of playground broadcasting disturbance from the source through technological means.

　　2、 Plan deployment

The Qingting Acoustic Engineering team conducted on-site research and visits at the Fourth Kindergarten in Weiyuan County. The activity area of the kindergarten is a small playground, which is adjacent to residential areas and office buildings, and is close to the other two primary and secondary schools on the southwest and northwest sides.

After professional sound field design, Clear Listening Acoustics has deployed two quiet playground systems (campus directional sound system) on the south side of the playground for the fourth kindergarten in Weiyuan County. The pleasant series enables the front directional sound range of the equipment to effectively cover the playground, and the sound on both sides and the back of the equipment rapidly attenuates without affecting the normal teaching environment. At the same time, it bids farewell to the problems of traditional broadcast reverberation and sound asynchrony, achieves sound field balance, and improves speech clarity and comprehensibility.

　　3、 Technical advantages

The Clear Listening Acoustic Quiet Playground System (Campus Directional Sound System) is based on the core directional sound technology of Dujia, and uses local sound field control technology and Dujia's specialized A-AFC algorithm to overcome the problem of controlling the sound field at the back of the system, achieving "sound locking" of the sound field behind the equipment. The maximum sound pressure difference between the front and rear of the equipment can reach 40dB, and the sound can propagate within a controllable pointing range, effectively reducing noise interference to residential areas and returning quietness to the public.

1. Technology noise reduction

Concentrate the sound in front of the device to produce sound, with a maximum sound pressure difference of 40dB between the front and rear, reducing interference to the surrounding area and achieving source prevention and control.

2. Directional sound transmission

By utilizing the directional sound generation technology and local sound field control algorithm of Quanqiu Lingxian, sound directional propagation and precise coverage can be achieved.

3. Balanced coverage

Breaking through the barriers of low-frequency technology, achieving 125Hz surging bass and balanced coverage of the entire playground area across all frequency bands.

4. Remote control

Equipped with a sound perception platform cloud control system, it can remotely control sound sources, sound zones, etc., making operation convenient.

5. Adjustable sound angle

Flexible adjustment of the sound angle of "low, medium, and high" speech can solve the problem of crosstalk and improve the utilization rate of the playground.

　　4、 Effect evaluation

After the implementation of the Clear Listening Acoustic Quiet Playground System (Campus Directional Sound System), nearby residents expressed great satisfaction with the improvement of the disturbance caused by broadcasting on the playground. The school leaders also highly praised the noise reduction effect of the system and the meticulous after-sales service guidance for clear hearing acoustics.

At present, the Clear Listening Acoustic Quiet Playground System (Campus Directional Sound System) has been implemented and applied in over 300 cities and 4000 schools across the country, effectively promoting the harmony of the campus sound environment and promoting the construction of smart "sound state" campuses through technological means. In the future, Qingting Acoustics will continue to iterate and upgrade its products, bringing users a better sound experience.