Making Environments Safer for those with ASD
8.2 Methods .1 – Apparatus
8.2.1.1 – Visual
Overview of the visual environment
In order to assess the visual environment over the course of a day, the auditor took pictures, using a Sony Cybershot DSC-WX7 digital camera.
Luminance and Chromaticity
The luminance and chromaticity were measured using a Minolta CS-100 chromameter.
8.2.1.2 – Auditory Sound level meter
The sound level was established using a CR:152B Optimus Yellow Sound Level Meter with Data Logging, which was calibrated prior to each measurement.
Field recorder
The auditory environment was recorded using a Roland R-09HR field recorder. Output files are uncompressed 16-bit .wav type, with a sample rate of 44.1kHz.
8.2.1.3 – Olfactory
Measurement of olfactory environment
There is no affordable, mobile technology currently available to measure olfactory environments. Thus, this portion of the Sensory Audit must be assessed using a human observer with typical or better-than-average olfactory threshold, discrimination and identification skills. The auditor’s observations are noted on the form shown in Appendix G.
Verification of olfactory ability
In order to identify a suitable individual to fulfill the olfactory aspect of the Sensory Audit, the Sniffin’ Sticks Extended Test is administered. This is a method of testing
chemosensory performance using ‘pens’, with various odorants diluted in propylene glycol (to a volume of 4 ml) (Hummel et al., 1997). See section 7.2.3.2 for more information.
We required the auditor to be either more sensitive than or within one SD of the norms published in Hummel et al., 2006. The norms, along with the olfactory auditor’s scores on each measure, are displayed in Table 8.1. Note that higher scores indicate superior
performance, with the highest possible score being 16.
Table 8.1 – Details of olfactory performance of auditor and norms for male between 36 and 55 (Hummel et al., 2006)
Norms Auditor (male; 48 yrs)
Threshold 8.43± 1.74 12.5**
Discrimination 11.94 ± 1.12 11.0*
Identification 13.10 ± 0.94 14.0*
* within norms for age group; **higher sensitivity than norms for age group
8.2.2 – Procedure
8.2.2.1 – VisualAn overview of the procedural protocol for the visual Sensory Audit is given in Appendix H.
Overview of the visual environment
Multiple photographs were taken of the environment over the course of a working day.
There were at least six viewpoints (ceiling, floor and all four walls) with extra photographs taken of any visual stimuli of interest (e.g. a colourful print/lighting/view from window etc). The reason for this was to a) assess whether we can identify any specific visual issues that may be present and b) to determine how the ambience in the room changes with time/weather/lighting etc.
Luminance and chromaticity
Luminance levels and chromaticity coordinates were recorded for 2-5 points of each
viewpoint photographed, using the luminance and colour meter detailed in section 8.2.1.1.
As with the photographs, these measurements were taken at multiple points over the course of a working day. Specific areas within each scene were identified and measured:
• the Macbeth colour checker reference white (included in the photograph)
• the natural bright point in the scene
• the darkest point
• any particularly strong colours in the scene
• ambient colour
• ambient luminance
8.2.2.2 – Auditory
An overview of the procedural protocol for the auditory Sensory Audit was given in Appendix I.
Ambient noise
The ambient auditory environment was assessed by determining the sound level using the sound level meter detailed in section 8.3.1.2. In addition, the auditory environment was recorded in order to identify a) specific peaks and troughs in the sound level data and b) any particular noises that should be recorded in isolation and analysed. Snapshots of the ambient noise were recorded at multiple points over the course of a working day, and used to identify the specific noises which would be analysed in depth.
Specific noises
Noises to be recorded were identified by a) the information gathering session, b) disclosure of any pre-identified auditory issues and c) during the assessment of the ambient noise.
The equipment detailed in section 8.2.1.2 was used to record the noise and determine the sound level simultaneously. Efforts were made to isolate the noise from any ambient sound prior to recording, in order to assess the acoustic qualities.
8.2.2.3 – Olfactory
An overview of the procedural protocol for the olfactory Sensory Audit is included as Appendix J.
The designated auditor assessed the olfactory environment, by entering the designated area and focusing on any odours. Odours were named if possible, rating the intensity on a scale of 1-5 (very faint – faint – noticeable – strong – overpowering). If they could not name the odour, they attempted to describe it. These details were recorded on the form shown in Appendix G. After approximately 2 mins, the participant should not be able to identify any new odours (as they become quickly habituated to the odours in the environment). As a result, they removed themselves to clear air (a previously identified area or outside) and given a break for 10 minutes to clear their adaptation to the environment before reassessing
the area. Each room/space being assessed was done so in this manner. As in the visual and auditory audits, the olfactory audit was repeated multiple times over the course of a working day.
8.2.3 – Data Analysis
8.2.3.1 – VisualLuminance
We were able to determine the amount of light that is emitted from a particular area by recording the luminance of certain points in a given environment. Luminance was
measured in candelas per metre squared (cd/m2), which enabled us to quantitatively assess the brightness of various stimuli in a given environment.
Chromaticity
An estimation of colour was obtained, using conversion from x, y and Y values to CIE 1931 colour space (Wysecki & Styles, 2000).
8.2.3.2 – Auditory Ambient noise
Min, max and mean sound levels (in A-weighted decibels (dB(A): an expression of how loudly a sound is perceived by the human ear, by accounting for frequency as well as sound pressure)) were determined using the sound level meter and compared across a) different environments and b) time.
Specific noises
Specific sounds are analysed using the program Psysound 3 (Cabrera, Ferguson, Rizwi, &
Schubert, 2008). Using a calibration file of a known sound level, the audio content from the field recorder was analysed for various acoustic properties:
• Loudness
o This is an estimation of the subjective experience of sound intensity (rather than the objective sound pressure, measured by the sound level meter)
• 1/3 Octave Frequency
o This details the frequency composition of the sound
• Sharpness
o This is a measure of the high frequency composition of a sound (measured in acum)
• Roughness
o This is a measure of the subjective impression of rapid amplitude change (measured in asper)
8.2.3.3 – Olfactory
Intensity and presence/absence of odours were charted across time.
8.3 Results
The pilot Sensory Audit was developed in order to help individuals with ASD by providing a method of objectively assessing sensory environments, as well as recommendations for the amelioration of such environments. In this section, the development of the Sensory Audit, as well as the results of the pilot Sensory Audit will be reported.