Software development update: The IRIS toolbox grows

Software development update: The IRIS toolbox grows

What does IRIS do?

IRIS is the first widely available, commercial 3D acoustic impulse response measurement and visualisation system developed by Marshall Day Acoustics.

IRIS has the unique ability to carry out a broad set of room acoustics measurements, including 3D impulse responses, quickly and easily. The ease of use that IRIS offers can mean less time and cost on site for data acquisition and quicker reporting of results through more efficient data post-processing.

IRIS is also a particularly good collaborative tool as it can visualise the way sound behaves in rooms for other disciplines on design teams, or user groups and stakeholders on a project.

New features

IRIS currently allows consultants to accurately measure a range of acoustic parameters including many which have traditionally been very difficult to obtain, such as lateral fraction. Recently, our development team has been working behind the scenes to expanding IRIS’s toolbox even further.

The latest version is nearly complete and new features will allow users to measure intelligibility metrics.

New IRIS tools will measure:

  • speech intelligibility (STI according to IEC 60268-11 Ed. 4)
  • spatial decay rate (D2,S)
  • level of speech at 4 m from source (Lp,A,S,4m)
  • distraction distance (rd)
  • privacy distance (rp)
  • VDI 2569 room acoustic class

These new metrics are calculated according to procedures detailed in two recently published office acoustics standards, ISO 3382-3:2012 Acoustics -- Measurement of room acoustic parameters -- Part 3: Open plan offices and VDI 2569:2016-02-Draft Sound protection and acoustical design in offices.

IRIS on show

The new suite of measurement options will be demonstrated at the Akustikbüro Rahe-Kraft GmbH stand at the acoustics conference DAGA 2018 ( in Munich in March. 

This will be followed by a general one-day IRIS seminar in Taipei on April 10 (

For more information about IRIS, visit the IRIS website.

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