How do shock absorbers reduce noise by mitigating vibrations?

Sound is ubiquitous in our daily lives. From birdsong outside our window in the early morning to the hustle and bustle of traffic on city streets, and even the noises from our neighbors next door, these sounds are essentially produced by the vibration of objects. When an object vibrates, it causes the surrounding air molecules to vibrate, forming sound waves that propagate and are eventually perceived by our ears. However, when these sounds become noise that interferes with our normal lives, work, and rest, how to effectively reduce noise becomes an important issue, and shock absorbers are the key sound insulation materials for solving this problem.

The core function of a vibration damper is to reduce noise by reducing the vibration of a noise source. Its working principle is based on the energy conversion and absorption principles of physics. When the vibration generated by noise is transmitted to the damper, the special structure and materials inside the damper absorb, convert, or disperse the energy of the vibration, thereby weakening the intensity of the vibration and reducing the propagation of noise. Depending on the installation location and function, vibration dampers are generally divided into ceiling vibration dampers and wall vibration dampers, each playing a unique role in noise reduction.

Ceiling vibration dampers, typically installed inside the ceiling, are an effective solution for dealing with noise from upstairs neighbors. In residential environments, noise from upstairs residents' daily activities, such as dragging chairs, children playing basketball on the floor, running, and jumping, all vibrate through the floor slab and propagate downwards. Ceiling vibration dampers act like silent guardians, absorbing and buffering this vibrational energy, significantly reducing the noise intensity heard by downstairs residents. Imagine the originally noisy and jarring dragging sounds becoming faint and muffled after being processed by ceiling vibration dampers, creating a quieter and more comfortable living space for downstairs residents. However, ceiling vibration dampers also have certain limitations. Due to their structural design, they are usually quite long, requiring a significant amount of ceiling height for installation. For houses with already low ceilings, installing ceiling vibration dampers may make the interior space feel even lower and more oppressive, affecting the visual experience and comfort of the residents.

Wall-mounted vibration dampers are primarily installed on walls and are suitable for various scenarios. When our room is adjacent to other residents' rooms or near an elevator shaft, sounds from conversations and televisions in the next room, as well as mechanical vibrations and noise from the elevator, will be transmitted through the walls. In this situation, wall-mounted vibration dampers play a crucial role. Through their unique damping structure and materials, they effectively block the transmission path of vibrations within the wall, reducing noise transmission. Moreover, compared to ceiling-mounted vibration dampers, wall-mounted dampers are shorter and require less space during installation. Typically, the installation method involves installing a joist, installing the damper, filling with sound insulation cotton, and then covering with plasterboard. The overall thickness is only about 9cm, which does not significantly compress the interior space. While achieving good noise reduction, it also maintains the integrity and aesthetics of the interior space.