ITS will participate in a soundproofing project for teaching and training rooms in Paris (France) to improve their acoustic quality.

It will be a question of alleviating the mediocrity, in terms of sound comfort, of a recent construction, devoid of any acoustic material, i.e. likely to significantly absorb sound, with particularly harmful consequences as regards the use of these teaching and training rooms (in terms of intelligibility of speech which is very poor there, while obviously fundamental in terms of functionality):

  • difficulty in understanding for the people to whom education and training are delivered
  • tiredness of the speakers, who struggle to speak
  • arduousness of exchanges between people, whatever their status

The same causes producing the same effects, such situations are unfortunately also not rare in schools and universities classrooms, or in nursery activity rooms.

An on-site diagnosis (the rooms being unoccupied, but normally furnished) revealed (thanks to a dedicated electroacoustic equipment, involving a noise generator and a microphone) reverberation times (characterizing the temporal sound decay) abnormally high (for premises with such a destination), but logically resulting from the lack of precautions taken, during construction and then fitting out, in terms of materials used as for their acoustic properties, for what the correlation with the inconvenience of users of these rooms is well known.

The clarification of reference values ​​appropriate to the case, being ipso facto also values to be targeted ​​for the improvement of the situation, in terms of the acoustic performance indicator that, in such closed spaces, the reverberation time is at mid-high frequencies (i.e. in the frequency bands of central frequency 500 Hz to 2000 Hz) allowed the definition, both in quality (in terms of acoustics, illustrated by the sound absorption coefficient for these frequencies) and in quantity (number of m2 to be installed), of specific soundproofing materials, likely to remedy the problem posed by this obvious lack of acoustic comfort.

The case study, which involved predictive acoustics calculations, led to the manifestation of the usefulness of considering absorbing elements with high acoustic absorption (i.e. with a Sabine factor close to 1), suspended in under face of the ceiling slab (sometimes called, we do not know why "sensors").

Their installation was planned horizontally, a precise layout having made it possible to define locations compatible with the electrical networks (visible cable trays), the ventilation / air conditioning network (visible ducts) and the suspended lighting devices.

These suspended acoustic elements will, as far as possible, be supplemented by absorbent wall panels, without which the lack of uniformity of the distribution, on the different walls of the premises, of surfaces having a sound absorption coefficient sufficiently high would be an obstacle to a substantial improvement in sound comfort following the installation of acoustic correction devices.

There is no doubt that after such soundproofing action, these teaching and training rooms, previously unsuitable for their purpose, will contribute to improve the knowledge and skills of the people to whom lessons and upgrade sessions are given, as well as to make better working conditions for instructors.