I. According to tests conducted by Intertek, an internationally recognized testing organization, the sound absorption performance of Silence Tech sound-absorbing nonwoven fabric is as follows:
Noise Reduction Coefficient (NRC): 0.7–0.8 (meaning that this material can absorb approximately 70%–80% of incident sound energy in the mid-to-high frequency range).
Sound Absorption Class: Class I–II (classified as a high-efficiency sound-absorbing material according to GB/T 16731-1997).
Excellent sound absorption in the mid-to-high frequency range: In the core vocal and broadcast frequency range of 250 Hz–5,000 Hz, the sound absorption coefficient (αs) remains stable between 0.60 and 0.78, with peaks occurring at 500 Hz (0.78) and 630 Hz (0.77).
Physical Properties: With a thickness of only 0.2 mm and a surface density of 65 g/m², this material is extremely lightweight and thin.
II. Contribution to “Reducing Reverberation Time (RT60)”
Excessively long reverberation time is the primary cause of “noisy, booming” conditions in large public spaces.
Highly Effective Reduction of Reflected Sound Energy: With an NRC as high as 0.7–0.8, this material effectively “absorbs” sound waves when applied over large areas on ceilings, walls, or columns. It significantly reduces multiple reflections between hard surfaces (such as glass, stone, and metal), thereby markedly shortening the space’s reverberation time.
Improves acoustic uniformity: In high-ceilinged spaces such as airports and high-speed rail stations, sound is prone to producing severe flutter echoes. This material’s high absorption characteristics in the mid-to-high frequency range rapidly attenuate mid-to-high frequency reflections, eliminating the “buzzing” or rumbling sensation within the space, reducing overall ambient noise, and creating a clearer, more comfortable listening experience.
III. Contributions to “Improving Speech Intelligibility (STI)”
Speech intelligibility (Speech Transmission Index, STI) directly determines whether broadcasts can be heard clearly and whether conversations are effortless.
Precise Coverage of the “Human Voice and Broadcast” Golden Frequency Band: The core frequencies of human speech and public broadcasts are concentrated between 250 Hz and 4,000 Hz. Test reports show that this material’s sound absorption coefficient in this frequency band ranges from 0.62 to 0.78. This means it can significantly absorb the “reverberation tails” that interfere with speech intelligibility, making direct sound (such as that emitted by public address speakers) stand out more clearly.
Improved Signal-to-Noise Ratio: By reducing ambient reverberation noise, the “signal-to-noise ratio” of public address announcements is enhanced. Even during peak hours with heavy foot traffic and high background noise, passengers and staff can effortlessly hear flight/train information and public announcements.
IV. In-Depth Analysis of Typical Application Scenarios
1. Airport Departure Lounges & High-Speed Rail Stations (Large Spaces, High Ceilings, High Foot Traffic)
Challenges: Due to the massive volume of these spaces and the extensive use of glass curtain walls and stone flooring, reverberation times are extremely long; broadcast audio tends to become muddled, while the sounds of crowd conversations coalesce into massive low- and mid-frequency background noise.
How Silence Tech acoustic Nonwoven Helps:
Drastically Improved Broadcast Clarity: Its excellent sound absorption performance in the 500 Hz–2,000 Hz range ensures that boarding and ticket-checking announcements are crystal clear, reducing the number of missed flights or trains—and the resulting anxiety—caused by passengers failing to hear announcements.
Reduced Perceived Crowd Noise: By absorbing mid-frequency reflections generated by large crowds conversing, it lowers the overall ambient background noise in the hall, enhancing the “sense of tranquility” and passenger experience at high-end transportation hubs.
2. Subway Stations (Narrow, Elongated Spaces; Hard Reflective Surfaces; Train Noise)
Challenges: Platforms and concourses are typically narrow and elongated, with walls often made of tile or concrete, which are highly prone to severe “echoes” and “standing waves”; the noise from trains entering and exiting the station is loud, easily drowning out safety announcements.
How Silence Tech Acoustic Nonwoven Helps:
Eliminating Echoes in Long Corridors: When installed over large areas on platform ceilings or side walls, it interrupts the sound wave reflection paths in narrow, elongated spaces, eliminating severe flutter echoes.
Ensuring Clear Communication of Safety Information: In the noisy environment of a train pulling into the station, a high-definition sound field ensures that emergency broadcasts and routine announcements are clearly heard by passengers, enhancing operational safety.
3. Office Buildings (Open-Plan Offices, Conference Rooms, Hallways)
Challenges: Open-plan offices are often filled with the clamor of voices, lacking speech privacy; in conference rooms, excessive reverberation can make video conferences difficult to hear and lead to fatigue during meetings.
How Silence Tech Acoustic Nonwoven Helps:
Enhancing Speech Privacy and Focus: It absorbs reflected sound from conversations in open-plan offices, shortens the distance sound travels, reduces mutual interference, and improves employee focus.
Optimizes the Acoustic Environment for Meetings: When installed on meeting room walls, it eliminates echoes, making both in-person conversations and online video conferences sound crisper and clearer, thereby reducing auditory fatigue.
V. Comprehensive Engineering Advantages and Optimization Recommendations
Extremely Thin and Lightweight (Ideal for Engineering Applications) This material is only 0.2 mm thick, with a surface density of 65g/m².
In existing or space-constrained environments such as airports, high-speed rail stations, and subway stations, traditional, bulky acoustic panels (such as polyester fiber panels and fiberglass panels) often take up too much space or detract from the aesthetic appeal of the design. Mi Jing nonwoven fabric can be applied directly—much like wallpaper—to existing perforated walls, glass surfaces, columns, or even the back of ceilings, enabling “invisible” acoustic retrofitting that perfectly aligns with the minimalist aesthetics of modern architectural design.
2. Optimization Recommendations for Low-Frequency Noise Report data shows that this material’s low-frequency sound absorption coefficient ranges from 0.37 to 0.59 at 100 Hz–200 Hz. For an ultra-thin material measuring just 0.2 mm, this low-frequency performance is exceptional. However, in high-speed rail and subway stations, train operations and large air conditioning units generate significant amounts of low-frequency noise.
Recommendation: During installation, use a stud system and leave a rear cavity (e.g., 50 mm–100 mm), or fill the cavity with eco-friendly acoustic foam. According to acoustic principles, adding a rear cavity can significantly improve the material’s sound absorption coefficient in the 100 Hz–250 Hz low-frequency range, thereby achieving optimal noise reduction across the entire frequency spectrum.
Summary: With its robust performance metrics—an NRC of 0.7–0.8 (Class I–II) and ultra-thin 0.2 mm profile—Silence Tech sound-absorbing nonwoven fabric is the ideal solution for addressing the common issues of “long reverberation, muffled public address systems, and noisy environments” found in airports, high-speed rail stations, subway stations, and office buildings. It delivers significant reductions in reverberation time and improvements in speech intelligibility with minimal space requirements.
