CA-3175563-C - ACOUSTIC SYSTEM

Abstract

An acoustic system (100) for improving the acoustic quality in a room (102) for speech, the acoustic system (100) comprising a room (102) having a first zone (A) and a second zone (B), the system further comprising a ceiling (104) of the room (102), the ceiling (104) comprising a plurality of ceiling tiles (110, 112), wherein the ceiling tiles comprises a first group of ceiling tiles (110) having sound absorbing properties and a second group of ceiling tiles (112) having sound diffusing properties.

Inventors

• Emma Arvidsson
• Erling Nilsson

Assignees

• SAINT-GOBAIN ECOPHON AB

Dates

Publication Date

20260505

Application Date

20210415

Priority Date

20200421

Claims (1)

1. 22 CLAIMS: 1. An acoustic system for improving the acoustic quality in a room for speech, the acoustic system comprising a room having a first zone and a 5 second zone, the first zone comprising a first end of the room and the second zone comprising a second end of the room opposite the first end of the room, the system further comprising a ceiling of the room, the ceiling comprising a plurality of ceiling tiles, wherein the ceiling tiles comprises a first group of ceiling tiles having sound absorbing properties and a second group of ceiling 10 tiles having sound diffusing properties, wherein the first group of ceiling tiles comprises ceiling tiles being arranged in the second zone and the second group of ceiling tiles comprises ceiling tiles being arranged in the first zone and being configured for reflecting sound to the first zone and to the second zone. 15 2. The acoustic system according to claim 1, wherein the first zone is a presentation zone and the second zone is an audience zone. 3. The acoustic system according to claim 1 or 2, wherein the ceiling is a suspended ceiling, a direct fixed ceiling or a free hanging ceiling unit. 4. The acoustic system according to claim 2 or 3, wherein the ceiling comprises a grid of profiles supporting the ceiling tiles. 5. The acoustic system according to any one of claims 2 to 4, wherein the 25 second group of ceiling tiles covers at least 5% of a ceiling area of the ceiling. 23 6. The acoustic system according to claim any one of claims 2 to 5, wherein the second group of ceiling tiles covers at the most 25% of a ceiling area of the ceiling. 5 7. The acoustic system according to any one of claims 2 to 6, wherein the first group of ceiling tiles comprises ceiling tiles mounted in the second zone. 8. The acoustic system according to any one of claims 2 to 7, wherein the second group of ceiling tiles are hollow having a front surface provided with at 10 least one opening facing the room, wherein the volume of a hollow portion of the ceiling tile is between 0.02 m3 and 0.04 m3. 9. The acoustic system according to any one of claims 2 to 7, wherein the second group of ceiling tiles are hollow having a front surface provided with at 15 least one opening facing the room, wherein the volume of a hollow portion of the ceiling tile is 0.03 m3. 10. The acoustic system according to claim 8 or 9, wherein the second group of ceiling tiles are configured to absorb sound having a sound frequency 20 below 500 Hz. 11. The acoustic system according to claim 8 or 9, wherein the second group of ceiling tiles are configured to absorb sound having a sound frequency of 125 Hz. 12. The acoustic system according to claim 2, wherein the presentation zone covers a presentation position from which a speaker is intended to address an audience. 24 13. The acoustic system according to claim 12, wherein ceiling tiles from the second group of ceiling tiles are arranged directly above the presentation position. 14. The acoustic system according to any one of claims 10 to 12, wherein ceiling tiles from the second group of ceiling tiles are arranged covering an area of the suspended ceiling from the presentation position extending towards the second zone. 15. The acoustic system according to any one of claims 2 to 14, wherein ceiling tiles from the second group of ceiling tiles are arranged in the audience zone. 15 16. The acoustic system according to any one of claims 1 to 15, wherein ceiling tiles from the first group of ceiling tiles are arranged in the first zone. 17. The acoustic system according to any one of claims 8 to 11, wherein the at least one opening has an opening surface area of between 200 mm2 and 20 300 mm2. 18. The acoustic system according to any one of claims 8 to 11, wherein the at least one opening has an opening surface area of 260 mm2. 25 19. The acoustic system according to any one of claims 1 to 18, wherein the second group of ceiling tiles comprises ceiling tiles having a front surface facing the room having a shape selected from the group comprising: a single curved convex front surface, a double curved convex front surface, a multi-faceted convex front surface, an asymmetric at least partially inclined front surface, an asymmetrically curved convex front surface, an inclined concave front surface, an at least partially curved concave front surface and a multi-faceted concave front surface.

Description

1 ACOUSTIC SYSTEM Field of the invention The present invention relates to acoustics and to improvements in audibility and intelligibility of speech for an audience. More specifically, the present invention relates to an acoustic system for improving acoustic quality 5 in a room for speech. Background art In rooms which are intended to be used for presentations and/or giving lectures etc, such as a class room or a conference/meeting room, it is desired 10 to provide acoustics which are ideally suited for facilitating the transmission of sound, particularly speech, to the intended audience. The teachings herein pertain particularly to ordinary rooms as defined in ISO 3382-2. Acoustic quality for speech in an ordinary room encompasses not only speech intelligibility for the audience but also speaker comfort, i.e. the perceived 15 comfort that a person speaking receives in the room. In: "Measurement and prediction of voice support and room gain in school classrooms", D. PelegrinGarcia, J. Brunskog, V. Lyberg-Ahlander, A. LOfqvist, published in J. Acoust. Soc. Am. 131 (1), January 2012, is speaker comfort discussed and a parameter for quantification introduced. The parameter voice support is 20 related to sound strength G. There is probably an optimum value but more investigations are needed. Early reflections of the sound waves are generally considered favourable for the acoustic quality in a room for speech while late reflections are considered detrimental. A standardized measurement parameter of such 25 early reflections is speech clarity Cso, where the relationship between sound reflections before and after 50 ms are observed and where the former is considered early reflections and thus beneficial. Another parameter that is of importance is reverberation of different frequencies of sound, where excessive reverberation or reverberation time, T20, of certain sound 30 frequencies can cause discomfort and/or reduce intelligibility of the speech. Moreover, as mentioned, the sound strength G is also of importance. All 2 these factors/parameters are affected by the general design of the room as well as of if for instance a sound absorbent ceiling is provided in the room. Summary of the invention 5 In view of that stated above, the object of the present invention is to provide an acoustic system that alleviates some of the problems with prior art solutions and improves speech intelligibility and speaker comfort in a room provided with a sound absorbent ceiling. To achieve at least one of the above objects and also other objects that 10 will be evident from the following description, an acoustic system is provided according to the present disclosure. More specifically, there is provided an acoustic system for improving speech intelligibility, the acoustic system comprising a room having a first zone and a second zone. The system further comprising a ceiling of the room, the 15 ceiling comprising a plurality of ceiling tiles. The ceiling tiles comprises a first group of ceiling tiles having sound absorbing properties and a second group of ceiling tiles having sound diffusing properties. The first group of ceiling tiles comprises ceiling tiles being arranged in the second zone and the second group of ceiling tiles comprises ceiling tiles being arranged in the first zone and 20 being configured for reflecting sound to the first zone and to the second zone. The sound diffusing second group of ceiling tiles arranged in the first zone provides early reflections to both the first zone, which may be a presentation zone, which improves speaker comfort. Further still, the early reflections provided to the second zone, which may be an audience zone, improves the 25 speech clarity and sound strength in the second zone which improves speech intelligibility. Moreover, reverberation time for octave frequency bands which are considered relevant for speech intelligibility are also reduced. The ceiling may be a suspended ceiling, a direct fixed ceiling or a free hanging ceiling unit. 30 In one embodiment, the ceiling comprises a grid of profiles supporting 3 the ceiling tiles. The second group of ceiling tiles may further cover at least 5% of a ceiling area of the ceiling. The second group of ceiling tiles may further still cover at the most 25% of a ceiling area of the ceiling. The aforementioned 5 ratios provide a desired balance where the overall sound absorbing functionality of the first group of ceiling tiles is maintained while the second group of ceiling tiles provides a significant improvement in speech intelligibility and improved speaker comfort. The first group of ceiling tiles may comprise ceiling tiles mounted in the 1 0 second zone. The second group of ceiling tiles may further be hollow having a front surface provided with at least one opening facing the room. The volume of a hollow portion of the ceiling tile may be between 0,02 m3 and 0,04 m3 - preferably approximately 0,03 m3 . The hollow shape of each second group 1