The interactivity can occur immediately as soon as input data is taken to the system. For example, people can see an image projected into a screen is changing in real time as they’re moving in front of camera. As we say interactivity, the more sudden reaction is regarded as stronger in terms of real time processing. This results in facilitation of understanding about the system structure and the consequence from their movement, also it better enables the learning of the system interaction and the creation of interesting output.

 

Inversely, some art works intentionally require that people wait to see the feedback. This is related to human perception. Music is a great example of this; it is the art of time. When people hear music, they forget some parts and remember others. Once a musical idea is represented and the audience becomes acquainted with the material, they recognize the interactive sound that follows its pre-articulated progenitor more easily and understand the relationship between the original and modified sound in real time.

 

In interactive music performance- where the processed sound accompanies its live instrument counterpart- it is often difficult to detect the relationship between the live and processed sound. If not indicated on the program, some people believe the performance is of a live instrument and a tape (pre-made sound). On the contrary, in a piece with less interactivity in terms of the process, which converts input sound not quite in real time, the interactivity is clearer for audiences to comprehend. For example, computer records a little segment of input signal while performer plays, then as soon as the recording is finished, the computer modifies the sound and sends it to the speaker so that audiences hear the difference. In this way, audiences listen to not only the original musical ideas but their variation or transformation. Thus, they identify the audible interactivity between the live and computer sounds by catching the series made by the imitation of organic development. Furthermore with the understanding of the process, audiences imagine the various consequences while the computer records the real time performance. This involves audiences in listening to the procedure of interactive music, revealing the disparity between process and perceived interactivity.

 

The human ability to recognize images is higher than their capability to perceive sounds in interactive art installations or performances. From my experience with collaboration for interactive audio-visual performance, most of the performers identified the visual composition first, then started understanding the aspect of sound. The reference of the material used by each of the media types may cause differing perception. Normally, most of the video processes in interactive art deal with the live input image that comes through the camera placed in the installation space. According to the artistic intention, people often see their own reflection in the visual representation as well as the modified, distorted result over the reflection in real time. Therefore, people are well aware that the basic image source is coming from a real image of themselves. It leads people into the understanding of image composition in depth by enabling them to focus on the various outcomes according to their gestures in front of the camera or use of sensor control.