AkuLap module room acoustics DIN3382-3 for large offices (Code: 3303020)

Module for evaluation according to DIN EN ISO 3382-3:2012-05 (Acoustics - Measurement of room acoustic parameters - Part 3: Open-plan offices)

Important Notes

For a complete and standard-compliant measuring system you need:

• Akulap module DIN3382-3
• Akulap Raumakustik
• calibrated dodecahedron with amplifier
• Class 1 measurement microphone
• sound level calibrator class 1

background for room acoustics in open plan offices

It's now widely recognized that office acoustics significantly affect employee concentration and performance. Traditional approaches, guided by standards like ISO 3382-2 and DIN 18041, focused on minimizing reverberation time to reduce overall noise levels. This involved using absorbers to attanuate sound reflections, leading to a quieter office as people instinctively lowered their voices (the Lombard effect).

However, this approach often proved counterproductive. While it improved speech clarity, it also allowed conversations to be heard clearly across greater distances. This unintended consequence disrupted concentration, as people are naturally drawn to speech, even if unintentional, and subconsciously try to process it. Imagine a busy environment where a phone conversation is barely noticeable. Now picture that same conversation in a "classic" acoustically treated office – it becomes distractingly clear.

This realization led to the new DIN EN ISO 3382-3:2012-05 standard for open-plan offices, which prioritizes reducing speech intelligibility to create private conversation zones around individual workstations. Instead of reverberation time (RT60), the focus shifted to measuring sound levels and speech intelligibility (STI), as defined in DIN 60268-16. While reverberation still plays a role, STI provides a more comprehensive understanding of the acoustic environment.

In detail, the following parameters must be measured

• deflection distance, rD, in m
• confidentiality distance, rp, in m
• spatial decay rate of the A-weighted SPL of speech, DL2,S, in dB
• A-weighted SPL of speech at a distance of 4m, Lp,A,S,4m, in dB
• mean A-weighted background noise, in octave bands Lp, A,B, in dB
• distance from the sound source r

The deflection distance rD is the distance from the sound source at which the speech intelligibility STI falls below 0.5.

The confidentiality distance rp is the distance from the sound source at which the speech intelligibility STI falls below 0.2.

Lp,A,S,4m is the A-weighted nominal sound pressure level of normal speech at a distance of 4.0 m from the sound source. The measurement does not have to be made at a distance of 4 m, but this value is calculated by linear regression from other positions.

The external noise, Lp, A,B is the sound pressure level in octave bands, at the workplace during working hours, but when people are absent. All continuously present noises that are not caused by people should be measured, e.g. HVAC systems (heating, ventilation and air conditioning), traffic noise in the environment, office equipment or a system for the artificial generation of masking sound (sound masking).

The following requirements apply for a standard-compliant measurement

• The measurement must be taken in fully furnished condition
• The measurement is carried out without people, but with typical external noise
• A measurement of speech intelligibility according to DIN60268-16 is mandatory. The complete STI parameter set must be measured. The use of simplified methods such as STI-PA is not permitted. This means that devices such as the NTI AL1 or XL2 cannot be used.
• The measuring instruments must meet the requirements of DIN 61672- Class 1
• The measurement microphones must be omnidirectional (omnidirectional)
• The measurement is carried out in octave bands in the range from 125Hz to 8000Hz
• Speaker and microphone must be positioned 1.2m above the floor
• Omnidirectional loudspeakers (e.g. dodecahedrons ) are required. In the 2009 draft, these were preferred but not mandatory. The reason for this is that an employee does not speak exclusively in one specific direction.
• The level of the sound source must be calibrated in octave bands

sound source

The sound source must be omnidirectional and radiate evenly in all directions. This is achieved in the required frequency range by a dodecahedron in accordance with DIN140.

For the level measurement Lp,A,S,4m, a sound source is required whose sound power spectrum corresponds to an average value of normal human speech. These average values ​​summarize male and female speakers. The reference values ​​are based on ANSI S 3.5-1997 (R2007)

Under open field conditions, the following values ​​must be observed:

The sound source is delivered calibrated to exactly this octave level. This can only be measured under laboratory conditions. The loudspeaker and amplifier form a unit and are calibrated by us. This system should be checked regularly (annually) in a suitable laboratory, as the calibration cannot be checked under normal room conditions.

carrying out a measurement

First, the loudspeaker is placed at a typical head position of an employee. A minimum distance of 0.5m from tables and 2m from walls or other reflective surfaces must be maintained. All required parameters are then automatically measured at different distances from the sound source. The measurement positions should be in a line that runs across the workstations. Typically, six to ten measurement positions are used, but at least four. Only distances in the range of 2-16m are used for the spatial decay rate. The first measurement position must be at the closest workstation on the imaginary line.

In total, at least 2 positions of the sound source must be measured.

You can also receive training/instruction on this product at your location. The speaker is Dr. - Ing. Frank Jordan. We offer this service throughout Germany, the cost is 1500 euros per day (net plus VAT including expenses)

Please note that all prices in this webshop include VAT.

DIN EN ISO 3382-3:2022

The following changes have been made compared to DIN EN ISO 3382-3:2012-05:

a) normative references updated;

b) new single-number value, comfort distance added and confidentiality distance removed;

c) exclusive use of an omnidirectional sound source in all measurement phases highlighted;

d) terms (section 3), measurement conditions (section 4) and determination of single-number values ​​(section 5) clarified;

e) application of the impulse response method better described and a new Annex B added;

f) Section 6 "Precision" and an informative Annex D added;

g) STI is determined in accordance with IEC 60268-16 using the weighting factors α and β for the male gender;

Comfort distance

The comfort distance is the distance from the calibrated sound source at which the A-weighted sound level drops below 45 dB.
This distance is the minimum distance a person should have from a sound source in order not to feel disturbed.

The comfort distance describes the effect of spatial attenuation in the office, without taking into account the private conversation environment, the background noise level or sound masking.

Features

• Simple measurement of parameters accorrding to ISO 3382-3.
• Supports measurement via impule, noise or sinus sweep (LOG
• Sweep/Chirp)
• Includes wizard for fast and easy measurments. Training phase is very short. Automatic error detection
• Generates reports (HTML / PDF) according to DIN 18041 ISO 3382
• Simple export to Excel
• Measures RT60 with 1/3 ocatave resolution
• Import and Export of room impulse responses from/to .wav files
• Schroeder plot
• EDT T20 T30
• Clarity and definition
• STI, RASTI and STIPA (IEC 60268-16)