FWIW, I added an elliptical training machine to my larger listening room where my large OHM F5s reside yesterday. I had to do some significant re-arranging of furniture including a large cushioned couch. THe speakers remained where they are and have been for months now. Yes, the sound changed! I am of the opinion that any change to what resides in a listening room effects the sound. The only question is how much and in what way. Some effects are so small however as to not be noticeable or significant, at least to human ears.
I also have no doubt that placing certain objects close to electronic circuits may very well have an effect. Again the questions are how much, what is the change, and is it for the better or worse or perhaps even a mixed bag. I suspect the third case is the most common, ie many well designed tweaks produce a combination of both positive and negative effects. However, the mindset initially is to listen for anything that might be different as positive. Over the long term, the assessment might change as our thought patterns change. More mind/matter interaction.....
I also have no doubt that placing certain objects close to electronic circuits may very well have an effect. Again the questions are how much, what is the change, and is it for the better or worse or perhaps even a mixed bag. I suspect the third case is the most common, ie many well designed tweaks produce a combination of both positive and negative effects. However, the mindset initially is to listen for anything that might be different as positive. Over the long term, the assessment might change as our thought patterns change. More mind/matter interaction.....