There is some (disputed) evidence that ultrasonic sound can be perceived, although not necessarily heard in the conventional sense. I'm not clear what the connection is between this and beats, though.
Bats use ultrasonics directly (and possibly Doppler shift?). Not sure what this has to do with human perception.
Sound stage perception may be due to time delays and phase shifts rather than ultrasonics as such. However, low phase shift in the audible range requires a flat frequency response up into the ultrasonic range. The only snag with this is that most speakers, rooms etc. are much more lumpy than any competent amplifier.
Bats use ultrasonics directly (and possibly Doppler shift?). Not sure what this has to do with human perception.
Sound stage perception may be due to time delays and phase shifts rather than ultrasonics as such. However, low phase shift in the audible range requires a flat frequency response up into the ultrasonic range. The only snag with this is that most speakers, rooms etc. are much more lumpy than any competent amplifier.
Interesting so frequency beyond the hearing range may effect the sound stage! RFI is across a wide frequency band! If this was amplified / reproduced via the system could it smear the sound stage or change the sound of the reproduced music? Just a thought beyond previous comments.
Regards
M. Gregg
Most RFI is way above the audible range, so direct response is very unlikely. However, rectification and intermodulation of RFI will be in the audio range and in severe cases could even cause a bias shift so it has an indirect effect.
Hello,
This is not a stretch. Read the link to beat frequency. Combine two close in frequency, beyond yours and my hearing range, tones. Those frequencies will combine and create an audible lower frequency beat. Perhaps if you see it, check out MIT TechTV – Ripple Tank: Interference of Two Point Sources
What does this have to do with human perception of directional sounds? Everything.
DT
Everything that is beyond abilities of conscious analysis is disputed by those who don't know about subconscious perception.
The experiment I referred to was designed to show subconscious perception. It appeared to show it. However, some have pointed out possible weaknesses in the experiment. That is why I said the evidence is disputed. There is evidence. It is disputed. My personal view is that the experiment was good, but not watertight. It therefore serves to confirm the views of a believer, but will not convince a sceptic. On balance, I think it probably did show what it was trying to show - that we can detect the presence of ultrasonic sounds that we can't actually "hear". I don't jump to conclusions about the motivation of those who disagree.
People often confuse beats with difference frequencies. It is not necessarily true that two ultrasonic tones will produce an audible tone, although non-linearities in the hearing system might convert a beat into a tone. Beats are about adding tones. Difference frequencies are about multiplying tones. They are not the same thing! If the effect does happen, then it is more likely to create discord and unpleasant sounds than nice ones.
People often confuse beats with difference frequencies. It is not necessarily true that two ultrasonic tones will produce an audible tone, although non-linearities in the hearing system might convert a beat into a tone. Beats are about adding tones. Difference frequencies are about multiplying tones. They are not the same thing! If the effect does happen, then it is more likely to create discord and unpleasant sounds than nice ones.
Perception can be misleading !
In a previous life, I worked on flight simulators.
One day a pilot complained that the joystick did not feel realistic at slow speed. Unable to find any fault, I told the pilot that I had topped up the hydraulic oil and everything should be okay again. I had of course done nothing.
This "magic" seemed to do the trick and word spread about the great cure for joystick feel issues.
From that point on, at least once per week a pilot would "detect" the oil shortage and request us to top up the oil in the system to restore the correct feel.
It has always amazed me what people can convince themselves of.
I don't have the knowledge to say this is the case for the transformer question, I'm just pointing out what strange things we people are. 🙂
In a previous life, I worked on flight simulators.
One day a pilot complained that the joystick did not feel realistic at slow speed. Unable to find any fault, I told the pilot that I had topped up the hydraulic oil and everything should be okay again. I had of course done nothing.
This "magic" seemed to do the trick and word spread about the great cure for joystick feel issues.
From that point on, at least once per week a pilot would "detect" the oil shortage and request us to top up the oil in the system to restore the correct feel.
It has always amazed me what people can convince themselves of.
I don't have the knowledge to say this is the case for the transformer question, I'm just pointing out what strange things we people are. 🙂
You have just described the placebo effect. It is much much stronger than most people realise; even those who are aware of it are still subject to it.
Of course, you could have rubbed some hydraulic oil onto the casing of the simulator. Then you could claim that it improves the signals by acting as a dielectric for surface wave modes which would otherwise disrupt correct operation of the electronics. Complete nonsense, but it sounds sufficiently "scientific" to convice people.
I don't know whether the OP heard a genuine effect or not. Mains interference or the placebo effect are the two most likely explanations, as I said right back at the start. It is unwise to dogmatically assert one, and pour scorn on the other.
Of course, you could have rubbed some hydraulic oil onto the casing of the simulator. Then you could claim that it improves the signals by acting as a dielectric for surface wave modes which would otherwise disrupt correct operation of the electronics. Complete nonsense, but it sounds sufficiently "scientific" to convice people.
I don't know whether the OP heard a genuine effect or not. Mains interference or the placebo effect are the two most likely explanations, as I said right back at the start. It is unwise to dogmatically assert one, and pour scorn on the other.
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