1. Can Sound-Insulation Sponges Completely Block Sound?

This is a common misconception. The core function of sound-insulation sponges is sound absorption rather than sound insulation. Its working principle is to convert sound wave energy into heat energy for dissipation through the porous structure inside the sponge, reducing the reflection and reverberation of sound indoors, so as to lower the interference level of noise. However, in addition to airborne sound transmission, sound also propagates through structural-borne sound, on which sound-insulation sponges have barely any effect. To achieve real sound insulation, it is necessary to use it together with sound insulation materials such as sound insulation felts and sound insulation panels to form a composite structure of "sound insulation + sound absorption". In simple terms, sound-insulation sponges solve the problem of "loud echoes and noisy environments", rather than the demand of "not being able to hear people talking next door".

2. What Impacts Do the Density and Thickness of Sponges Have on the Sound Absorption Effect?

Density and thickness are two key parameters that affect the sound absorption effect. Generally speaking, for medium and high-frequency noise, sponges with a thickness of 5-10 cm and a density of 20-40kg/m³ have a good sound absorption effect; for low-frequency noise, thicker sponges are required, with a recommended thickness of usually over 15 cm, or a multi-layer composite structure can be adopted. However, higher density does not always lead to better sound absorption effect. Excessively high density will reduce the size of internal pores of the sponge, which will instead degrade the sound absorption performance. Noises of different frequencies need to be matched with sponges of corresponding densities and thicknesses, and appropriate specifications should be selected according to the main frequency range of the noise during purchase.

3. Which Has Better Sound Absorption Effect: Pyramid-Shaped Sponges or Wave-Shaped Sponges?

Pyramid shape and wave shape are the two most common profiles of sound-insulation sponges, and their sound absorption effects have their own respective focuses. The raised surface structure of pyramid-shaped sponges can increase the contact area with sound waves, delivering better sound absorption performance for medium and high-frequency noise. Meanwhile, it has a more professional appearance, and is often used in scenarios such as recording studios and live streaming rooms. The surface undulations of wave-shaped sponges are relatively gentle, which offers a more balanced sound absorption effect for broadband noise, with a softer visual look after installation, making it suitable for scenarios such as home theaters and music practice rooms. Under the same thickness and density, the sound absorption performance of the two profiles has little difference, and the selection should focus more on the installation scenario and visual effect.

4. What Is the Service Life of Sound-Insulation Sponges?

In a normal usage environment, the service life of sound-insulation sponges is usually around 5 to 8 years. However, the actual lifespan will be affected by multiple factors: long-term exposure to sunlight will accelerate the aging of the sponge due to ultraviolet rays, leading to hardening, discoloration and powder shedding; humid environments will cause the sponge to go moldy and deform, resulting in a significant drop in sound absorption performance; frequent physical squeezing will also damage the internal structure of the sponge. If obvious pulverization, hardening or peeling appears on the sponge surface, or the sound absorption effect degrades significantly, it means the sponge has aged and needs to be replaced. Keeping it dry and avoiding direct sunlight in daily use can effectively extend its service life.