Pracownia Akustyczna

The project concerned the library acoustics for the new building of the Wroclaw University Library.

Pracownia Akustyczna designed a project of selection and arrangement of loudspeakers in the chosen rooms along with the electroacoustic simulations for Voice Evacuation System (VES) installation.

VES is a public address system, which has to assure a proper speech intelligibility through the noise that increases during evacuation.

The acoustic designers had to determine if the Voice Evacuation System fulfils the basic requirements:

1. Proper VES design - a proper selection and arrangement of VES loudspeakers.
2. Library acoustics - the room acoustics of the rooms in which the Voice Evacuation System must work.

Pracownia Akustyczna made acoustic simulations for the rooms in which the library acoustics itself could be a problem.

The library acoustics was digitally simulated especially for the rooms:

• of large volume,
• with high ceilings,
• geometrically complicated.

Originally, the analysed room had been designed using only the finish materials of high sound reverberation, conducing reverberation noise.
What is more, high levels of acoustic background, which worsen speech intelligibility, could occur in the rooms strategic for evacuation.
Among the analysed rooms were:

• the main hall,
• storerooms,
• reading rooms and multipurpose halls,
• catalogue and book collection rooms,
• staircases,
• car parks

in those places a high level of acoustic background can be expected.

The digital simulation of library acoustics conducted on the digital models showed that in some of the analysed rooms it is impossible to obtain the values of speech intelligibility index required from VES or the reverberation time recommended by the library acoustics requirements.

Pracownia Akustyczna recommended the modifications of library acoustics by using the acoustic adaptation. During the consultation of the architectural designer, Jacek Rzyski, the materials which will improve the library acoustics and the Voice Evacuation System operation without disturbing the architectural vision have been chosen.