## 5 Discussion  
### Phase One: Spatial Audio Attention Testing  
Throughout Phase One, subjects in both groups displayed overall attention towards the presented auditory targets; however, those within the 3D audio group displayed showed higher levels of head orientation in the direction of audio events. These results demonstrate that despite reported impairments in interpreting ITD and ILD binaural cues associated with autism [65], spatial audio was capable of accurately attracting participants to the areas of the virtual environment applicable to the auditory stimulus's location.  
Individuals with autism have been recorded as having similar evoked brain responses to speech-like stimuli than their typically developed peers, but at the same exhibit less involuntary attention towards it [66; 67]. With this in mind, it would be expected that under the test paradigms of free exploration that measures involuntary attention, accuracy scores for speech stimuli to be the lowest. However, the findings from Phase One of this experiment are contrary to this for both condition groups, with the auditory event with the lowest scores being the crow (event 6). This auditory stimulus type would appear to be similar to the ambient environmental audio track and despite the lack of competing audio present the event was not unique enough to warrant participant attention. In the case of attention towards speech-like sounds in Phase One, these events are a combination of explosion and non-human speech-like stimuli, designed to create a unique audio cue that attracted attention towards them. Furthermore, studies have observed hyperactivity in the brain with response to novel auditory stimuli in children on the autistic spectrum [68].  
Research by [PERSON] and [PERSON] [69] revealed that despite audio cues being less accurate for sound source localization than accompanying visual cues, within a virtual environment audio-only cues are almost equally effective as visual only cues. In addition, when objects were placed outside of the participants field of view or subjected to occlusion of other visual objects, audio-only cues were more successful in the preliminary phase of object localization. This could serve as justification for the significant effect visuals accompaniments had on the overall accuracy scores for participants in the mono audio group. The visual representations would compensate for the spatial inaccuracies of the audio rendering. This would also account for the similar scores present in both groups for event three (e.g., bubble sound). This incorporated visuals that spanned a large area of the VE which would attract user attention once it arrived into the participant field of view.  
Exploration of the virtual environment is also illustrated in the positional data density plot (see Figure 7). For both conditions tracked horizontal movement was concentrated close to the starting position of \((x,y=0,0)\). Nonetheless, participants listening to spatialized audio displayed clear movement in the direction of both the auditory only and audio-visual cues. Due to the grouping of both audio-visual and audio-only events it cannot be confirmed which events encouraged participant exploration in those areas. However, the reduced amount of tracked data in the direction of event three does suggest that the larger visual stimuli negate the need for participant exploration of the VE.