Din 18041 audibility in rooms – requirements, recommendations and hints for planning (issue March 2016)
Types of use of rooms in room Group A:
A1 Music - predominantly musical performances.
Good audibility for unamplified music. Linguistic performances are only possible with certain limitations of speech intelligibility.
Examples: music-making with active playing and singing
A2 language/lecture - linguistic performances are in the foreground, usually from a (frontal) position. Simultaneous communication between several people in different places in the room is rarely performed.
Linguistic performances by individual speakers achieve a high level of speech intelligibility. Musical performances are usually perceived as too transparent and clear, but favorable for musical rehearsal work.
Examples: Court and Council, Hall Auditorium meeting Room School Auditorium
A3 language/lecture included-spaces of use A2 for persons who are particularly dependent on good language comprehension. (see Disability Equality Act)
Linguistic performances of individual speakers achieve a high level of speech intelligibility, also for persons with Höreinschränkungen or e.g. foreign language use.
Examples: Court and council, community Hall, auditorium, meeting room, school auditorium.
A3 Teaching/communication - communication-intensive uses with several simultaneous speakers distributed in space
Linguistic communication is possible with several (sometimes simultaneous) speakers.
Examples: classroom, differentiation room, meeting room, meeting room, conference room, seminar room, group room in children's day facilities, nursing facilities and retirement homes.
A4 Tuition/Communication inclusive-communication-intensive uses with several simultaneous speakers distributed in the space according to the type of use A3, but for persons who are particularly dependent on good speech comprehension. (see Disability Equality Act)
Linguistic communication is possible with several speakers (sometimes at the same time), also for persons with Höreinschränkungen or e.g. foreign language use.
Examples: classroom, differentiation room, meeting room, meeting room, conference room, seminar room, group room in children's day facilities, nursing facilities and retirement homes, video conference room.
A5 Sports - in sports and swimming pools communicate several groups (also at the same time) with different contents.
Linguistic communication over short distances is generally well possible.
Examples: Sports and swimming halls for almost exclusive use as a sports facility.
In the case of Group A, the audibility is achieved by a use-specific reverberation time as well as by a steering of the sound by means of a sensible positioning of absorbing and reflecting surfaces in the room. The basis for a good audibility of the room Group A is the acoustically coordinated interaction of room geometry, size and equipment as well as the overall noise pressure level. If the focus of use is in the area of voice communication, then there are three components to consider:
1. Speaker, 2 transfer and 3 listen/understand. They are influenced by sound reflections, reverberation and noise. For optimal voice communication over medium and long distances, with low to moderate speech exertion of the speaker (normal up to raised speech) as much direct sound as possible and clarity increasing initial reflections up to 50 ms after the Direct sound from the speaker to the listener. The aim is to achieve a considerable reduction in the interference caused by longer disturbing reverberations, long-delayed energy-rich reflections and noise.
The SetPoint t of the reverberation time is dependent on the type of use and the room volume for rooms of Group A and refers to the state of the room with 80% of the regular occupation. The DIN 18041 addresses a clear requirement for the reverberation time over the frequency in Group A rooms: the reverberation time should be as constant as possible with a tolerance of ± 20% over all octave bands from 250 Hz to 2000 Hz; At lower and higher frequencies, slightly larger deviations can be tolerated. The setvalues of the reverberation time for the five types of use A1 to A5 according to 4.2.2 are to be calculated according to the equations (see Din 18041) depending on the volume V. The proof of compliance with the required frequency-dependent reverberation time is carried out in accordance with the specifications of DIN Appendix A during the planning phase and, if necessary, after completion of the room by measurements. For the purposes of this standard, the frequency-dependent consideration of reverberation time is absolutely necessary.
For the rooms treated in this standard, a linear frequency-dependent course is usually to be pursued for the reverberation time. However, a moderate increase in reverberation time to low frequencies does not affect the audibility. In case of doubt, in rooms for speech information and communication, shorter reverberation times should be realized. In the case of multi-purpose uses, the value of the main use of intermediate values between the target values must be determined, unless the different requirements are taken into account by means of variable acoustic measures. The reverberation times apply to the relevant usage scenarios of the room, taking into account the sound absorption of the furnishing and of persons. In the case of usage scenarios, especially smaller cast densities should be considered, if these are to be expected.
Types of use of rooms of room Group B:
B1 rooms without quality of stay
Examples: entrance halls, hallways, staircases, etc. As a mere transport area (except for traffic areas in schools, children's day facilities, hospitals and nursing facilities)
B2 rooms for short term stay
Examples: entrance halls, hallways, staircases, etc. Transport areas with a quality of stay (reception area with waiting areas), exhibition rooms, switch halls, redressing in sports halls
B3 rooms for longer term stay
Examples: exhibition rooms with interactivity or increased noise (multimedia, sound-/Videokunst etc.), traffic areas in schools and daycare facilities (kindergarten, crèche, hoarding etc.), traffic areas with quality of stay in Hospitals and nursing facilities (e.g. open waiting areas), patient waiting rooms, room for breaks, dorms, dorms, operating rooms, treatment rooms, examination rooms, consultation rooms, dining rooms, canteens, laboratories, libraries, showrooms- Individual offices can be classified as B3.
B4 rooms with need for noise reduction and room comfort
Examples: reception/switch area with permanent work station, laboratories with permanent workplace, lending areas of libraries, output areas in canteens, residents ' rooms in nursing facilities, citizen Office, Office space (individual offices can be under B3 )-(Recommendations for office space and call center are discussed in detail in the guideline vdi 2569.)
B5 rooms with special needs for noise reduction and room comfort
Examples: dining rooms and canteens in schools, children's daycare facilities (kindergarten, crèche, hoarding etc.), hospitals and nursing facilities, working areas with particularly high noise levels (e.g. workshops, workshops, large kitchens, kitchen sinks), Call centers, control centres, safety centres, intensive care areas, waking stations, movement rooms in children's day facilities, play corridors and dressing facilities in schools and children's daycare centres (kindergarten, crèche, hoarding, etc.)
Individual offices can be classified according to DIN 18041 in the usage of B3, more people offices in the usage of B4. More precise specifications for office space, however, is the draft revision of the guideline VDI 2569 "Sound protection and acoustic design in the Office", which was developed in close coordination with the recast of Din 18041.
In the case of Group B, the audibility is to be achieved by lowering the mean ground level in the room and limiting the reverberation by means of an appropriate Raumbedämpfung (absorption). For rooms of Group B, the DIN 18041 recommends a minimum ratio of the equivalent absorption surface of the room to the volume of the room, A/V, to achieve the audibleness (each specific use specified). For rooms of room Group B, measures for Raumbedämpfung are recommended. This achieves a reduction of the mean ground level in the room and a limitation of the reverberation. In rooms of Group B, recommendations for the ratio of the equivalent absorption area A of the room to the volume V, in the following A/V ratio, are specified in the frequency range from 250 Hz to 2 000 Hz.
The above information and the calculation formulas of our acoustic calculator are taken from Din 18041:2017-03. But only in terms of reverberation time. However, the DIN 18041 contains further recommendations, e.g. on the geometric design of spaces and placement of absorption surfaces, noise pressure levels and the sound pressure (db).
The DIN 18041 can be ordered for a fee (€117.20 stand April 2017) at Beuth Verlag: https://www.beuth.de/de/norm/din-18041/245356770
You will find further technical papers with clear explanations at the Industry association office and Working World e.v. (IBA): https://www.iba.online/service/publikationen/