Reverberation control of work spaces and of other living areas in buildings is a specialty of ITS, having an extended experience for many applications (measurements, study-engineering, works).
Reverberation control of premises: quality / performance indicators
The quality / performance indicators of the premises (allowing to assess the need or not to carry out a reverberation control, and - where appropriate i.e. when it is required in view of regulatory or contractual obligations, or desirable with regard to normative criteria or other reference documents being of non-compulsory application - to quantify its extent, are physical quantities:
- for which reference values are the subject of consensus
- measurable, according to standardized metrological protocols
Depending on the context, and with the (notable) exception of opera houses, theatres, cinemas, concert halls, which require others, the quality/performance indicators for premises are generally, possibly, among the number of two:
- reverberation time
- sound level decay by doubling the distance
ITS human resources are experienced in the determination and use of such quality/performance indicators for premises, and have a perfect knowledge of everything that allows them to be used wisely.
Reverberation control of premises: measurements & studies
The measurements of the acoustic quality / performance indicators of the premises (wether requiring reverberation control or not) are carried out - on site, before or after soundproofing works - by a human resource (employed by ITS) duly qualified in physical measurements - with specialties in instrumental techniques -, with equipment (sound level meters, noise generators) checked and calibrated periodically; the analysis is made using specific measurement data processing software. Acquisition and exploitation of data are carried out not only for the purposes of the (binary) evaluation of the conformity of a room, or the establishment of sound maps, but in a more complete and detailed manner in order to make their use possible as part of the search for solutions to improve the acoustic situation (often: for noise reduction, or for improving the acoustic comfort of speaking and listening rooms).
Engineering studies and engineering / design services relating to the reverberation control of premises (subsequent to an on-site diagnosis or not), are carried out by an ITS acoustician engineer with all the skills required in building physics, using simulation (as applicable):
- as available from the market (based on sound rays tracing)
- developed by ITS human resources - in a Research and Development (R&D) context
The deliverables of a reverberation control study of a room by ITS include detailed recommendations relating to possible ways to progress, and the characteristics of appropriate soundproofing products and construction systems, as well as a clear and verifiable performance objective with a budget.
The quality management system for ITS engineering services, particularly with regard to the acoustic correction of premises, is periodically assessed in accordance with the requirements of the ISO 9001 standard.
Reverberation control of premises: works
The works marketed by ITS in connection with the acoustic correction of premises are carried out by specialized installation teams, who take the greatest care in the execution of their tasks according to methods guaranteeing the achievement of the objectives, not only in terms of acoustics but also with regard to appearance and finishes (work safety rules and planning are always respected).
Reverberation control of premises: ITS applications in terms of measurements, study-engineering, works
In relation to regulatory texts and standards, this consists in implementing (in various forms e.g. acoustic suspended ceiling, wall-mounted absorbent lining, screens, baffles and suspended absorbent elements) sound-absorbing materials, in quality, in quantity and in location satisfactory to the objectives and specific constraints of each project: acoustic performance, but also, and depending on the context: lightness and possibilities of fixing on the available supports, resistance to moisture, oxidation, cleanability, decorative function ...
- Reverberation control of work premises
- the Decree of 30 August 1990 regulates the decrease of the noise level by doubling the distance at source in the premises (workshops, production facilities) where machinery and apparatuses are to be installed, capable of exposing workers to a level of daily noise level greater than 85 dB (A), whether it is a room empty of any machine or production facility or premises after installation of machinery and production equipment
- the NF S 31080 standard (which is not mandatory) sets acoustic performance levels and criteria by type of space for offices (individual, collective, open space) and associated spaces (meeting / training room) , relaxation area, restaurant): reverberation time and spatial decay rate (as appropriate)
The reverberation control aims, for such applications, to reduce the reverberation of noise on partitions when it is likely to significantly increase the level of noise exposure of workers:
- Reverberation control of teaching establishments
- the Decree of 25 April 2003 regulates teaching and practical premises, administrations, libraries, information and documentation centers, music rooms, meeting rooms, teachers' rooms, medical premises and infirmaries , multipurpose rooms, dining rooms
The reverberation control aims, for such applications, to limit noise in nursery and elementary schools, colleges, high schools, regional institutions of special education, universities and institutions of higher education, general, technical or professional (public or private), by imposing reverberation time limits:
- Reverberation control of premises in health facilities
- the Decree of 25 April 2003 regulates the dining rooms, staff rest rooms, public reception areas, accommodation or care spaces, examination or consultation rooms, medical offices or consulting rooms, premises and circulations accessible to the public
The reverberation control aims, for such applications, to limit the noise, by imposing reverberation time limits:
- Reverberation control of sports halls
- the standard NF P 90207 sets maximum permissible values for the reverberation time (depending on the volume) and the sound decay values in space (depending on the area) for rooms reserved for the practice of some sports: gymnastics, athletics, volleyball, handball, basketball, tennis, fencing, table tennis
The reverberation control aims, for such applications, to reduce the noise:
- Reverberation control in institutions for childrens under 6 years
- in France there is no regulation nor standard, but nevertheless a broad consensus regarding the reverberation time of the atriums, games rooms - and activity - of the different sections, sleeping rooms, offices , medical rooms, staff rooms, halls and stairwells that may be crossed regularly by children
- Reverberation control of restaurants, bars, places with amplified music broadcasting
- in France there is neither a regulation nor a norm but a broad consensus regarding the reverberation time
- Reverberation control of operas, theaters, cinemas, concert halls
- (in addition to the reverberation time) clarity at 50 or 80 ms (C50, C80), early decay time EDT (Early Decay Time), speech transmission index STI, central time TS, definition D50, sound force G, lateral efficiency (LF and CFL).
The reverberation control aims, for such applications, to reduce the ambient sound levels:
The reverberation control aims, for such applications, to improve the sound comfort:
The reverberation control aims, for such applications, to adjust, with respect to needs whose evaluation is of great complexity, many performance indicators: