Regarding cancer treatment, wonder how much more advancement did they get on that polio treatment. Where lot of test subjects with a brain tumor was treated by injecting polio virus into them.
So what it's saying is that it's an area of space where sounds become incoherent due to interference from other sounds or reflections. So i'm assuming it affects the quality of audio recordings and the he is suggesting methods for minimizing its impact, such as using directional microphones or adjusting the distance between the microphone and the sound source. The post also touches on the importance of considering the circle of confusion in the design of recording spaces and in the placement of speakers for live events.
Audio engineers often use techniques such as microphone placement, reverberation, and equalization to control this circle of confusion and create the desired effect. For example, using a close-miking technique with a directional microphone can create a small circle of confusion and a sense of intimacy, while using a distant-miking technique with an omni-directional microphone can create a larger circle of confusion and a more spacious sound.