The importance of soundproofing in library

Soundproofing is crucial in libraries. In fact, we lose concentration every eight seconds on average: distraction is now a way of life, perpetual entertainment a habit. Even some experience silence as an anomaly; instead of appreciating it, we feel uncomfortable. There are places, however, where religious silence is necessary and obligatory. In order to contribute to the improvement of the quality of acoustic well-being in libraries, a number of interventions are necessary, not only in the structure but also in its context. In order to guarantee soundproofing requirements in libraries and school buildings, strategies and interventions aimed at reducing the propagation of sound waves (noise) within each room must be foreseen from the preliminary design. This is also possible through good sound insulation, as well as control of noise from internal sources (installations) and optimal reverberation.

Screening in building environments is one of the possible strategies to counter the propagation of external noise to the interior. In the most critical cases, it is also possible to provide acoustic barriers or spatial and architectural elements that can act as noise barriers. It should be emphasised that acoustic barriers are effective in reducing noise at medium-high frequencies, rather than at low frequencies. For this reason, it is necessary to act not only externally, but also and above all internally, by applying materials to walls, ceilings and floors that are suitable for acoustic improvement. From this perspective, the materials that are traditionally used to ensure acoustic well-being standards have the following physical characteristics:

• they must be very porous: by trapping air and making it static, the cavities within the material enable the acoustic capacity to be improved;
• they must be rough: the rougher the surface, the more difficult it is for sound waves to propagate; rough walls hinder the return reflection of the sound wave;
• raw materials (such as cork and pumice stone) with certain sound-absorbing qualities in building product mixtures contribute significantly to acoustic improvement. Pumice, in particular, is characterised by an alveolar structure with pores of varying size. The honeycomb structure gives it a high elasticity, which translates into excellent mechanical workability and sound absorption capacity for sound vibrations. It can be used either loose or mixed as aggregate in lightened thermo-soundproofing plaster mortars in inter-floor or counter-ground slabs, practicable roofing (Diathonite Acoustix and Diathonite Acoustix⁺). It is also used in the production of laying screeds that significantly improve the soundproofing of floors without affecting the mechanical resistance (Diathonite Screed and Diathonite Thermostep.047).