Wood is generally considered better for soundproofing compared to concrete. This is due to wood's ability to absorb and dampen sound waves more effectively than concrete, which tends to reflect and transmit sound more easily.

Wood's cellular structure allows it to absorb sound more efficiently. The spaces between the wood fibers can trap and dissipate sound energy, reducing the amount of noise that passes through. Additionally, wood can be treated with soundproofing materials or insulation to further enhance its sound-dampening properties. For instance, adding mass to wood structures, such as installing soundproofing panels or dense insulation, can significantly improve their soundproofing capabilities.

Concrete, on the other hand, is a dense and rigid material that reflects sound waves rather than absorbing them. While it can be effective at blocking sound from entering a space, it is less effective at preventing sound from escaping. Concrete walls are more likely to transmit noise through vibrations, which can be particularly problematic in high-traffic areas or when dealing with low-frequency sounds.

According to a study published in the Journal of the Acoustical Society of America, the sound absorption coefficient of wood is typically higher than that of concrete. For example, a solid wood panel with a thickness of 1 inch has an average sound absorption coefficient of around 0.7, while a similar thickness of concrete has an absorption coefficient of around 0.2. This means that wood absorbs 70% of the sound that hits it, while concrete absorbs only 20%.

In practical applications, such as in residential construction, wood framing is often used in conjunction with soundproofing materials to create a more effective sound barrier. For example, adding a layer of resilient channel between the wood studs and the drywall can help isolate sound vibrations and reduce noise transmission.

In summary, wood is generally better for soundproofing due to its ability to absorb sound waves more effectively than concrete. While concrete can be effective at blocking sound from entering a space, it is less effective at preventing sound from escaping and is more prone to transmitting noise through vibrations.