17.10.2009, 04:55 PM
tz tz tz , hab ich hier noch gar nix dazu beigetragen...
na denn:
gibts denn ein "Audiophiles Rauschen" ?
im prinzip - ja. wenn man nix davon hört !
wenn man es hört, ist es eben rauschen - und das ist störend, nichts anderes.
ein Audiophiles Rauschen ist aber möglich, sofern der pegel so gering ist, dass es nicht (!!!) als rauschen wahrgenommen wird
-> erklärung: jeder sensor, also auch unsere ohren, hat eine minimale schwelle, unterhalb der keine wahrnehmung erfolgt. wird nun zu einem solchen -eigentlich- zu kleinen sigal ein rauschen etwa gleicher grösse addiert , wird eine wahrnehmung möglich.
diese methode wird technisch auch dithering genannt und zb bei A/D-wandlern verwendet, um die auflösung im bereich des LSB zu verbessern bzw zu linearisieren.
im home-audio-bereich ist zusätzliches rauschen allerdings bei richtiger abhör-lautstärke völlig sinnlos, da alle tonträger bereits mehr als genug davon enthalten ! wird im studio bereits zt absichtlich, zt unabsichtlich dem signal hinzugefügt.
im home-audio-bereich kann also der effekt einer verbesserung der auflösung nur dann mit zusätzlichem rauschen möglich sein, wenn die abhör-lautstärke so gering ist, dass das ohnehin zb auf cd enthaltene rauschen deutlich unter der auflösung der (schlechten) home-anlage liegt. der zum signal hinzugefügte rauschanteil darf aber nicht als rauschen hörbar werden, sonst wird die auflösung wieder verschlechtert.
hoffe, dass das hiermit mal geklärt ist...
dazu noch ein beispiel:
verbesserung der empfindung an den fuss-sohlen durch zusätzliche vibration mit rausch-signal
quelle: http://www.spectrum.ieee.org/geek-life/p...cing-act/2
To prove that someone's sense of touch could be improved, we had to first find that person's sensory limits. Clinicians routinely do this by poking patients with either a standard kit of filaments of different stiffnesses or a vibrating probe. Finding the level at which the patient feels the force of the filament or the vibration of the probe quantifies that patient's sensitivity. By recording a person's performance while randomly switching the stimulation on and off, we can show whether the noise boosts sensitivity.
In experiments we performed in collaboration with Aristidis Veves at the Joslin-Beth Israel Deaconess Foot Center, in Boston, we showed that we could improve sensitivity on foot soles of people with diabetes through the use of vibrating insoles. The vibrations were so small that the patients could not feel them, removing any chance that they would be biased in favor of the noise.
These findings complement earlier work by our group showing that imperceptible random vibration could enhance sensitivity on the fingers of the young, the elderly, and stroke patients, as well as those with diabetes. Future research will focus on the ability of diabetic subjects wearing vibrating insoles to improve their gait and walking patterns to minimize uneven pressure points.
We've gone a step further, so to speak, from just measuring sensitivity in our work with older people. Here we are looking at how a little noise can help them stay on their feet. We hypothesized that a heightened sense of touch on the soles of the feet can be integrated into the sensory-motor control system that allows people to maintain their balance while standing still.
We asked test subjects to stand on a pair of vibrating insoles, with their eyes closed [see illustration, " Still Standing"]. We set the amplitude of the vibrational noise to a low level and then slowly increased it until the research subject could feel it. (This level is different for each person.) Then we dialed down the amount of noise until it was just under that level, which effectively blinds the subject as to whether the stimulation is on or off during the trials. We put a reflective marker on the subject's shoulder and tracked its horizontal position with a special camera system. In an attempt to quantify the subject's balance from his or her posture, we plotted the shoulder marker's movements while the noise was turned on and when it was off.
The result, called a stabilogram, is an incomplete measure of how stable the subjects were when standing -- there are too many joints between the shoulder and the feet to fully analyze posture from it. Nevertheless, the movement at the shoulder can tell us important things, such as how much a person sways before the internal control system makes a correction. In general, a tightening of the stabilogram indicates greater stability.
We performed the experiments with people in their 20s as well as people in their 70s, and we demonstrated a significant improvement in balance control in both groups when noisy vibration was applied to the soles of the feet. In particular, we found that both young and old subjects swayed considerably less when the vibrating insoles were turned on.
The improvement was more pronounced for the older group -- so much so that when the septuagenarians wore the vibrating insoles, they swayed similarly to the twenty-somethings without vibrations.
Our results also fit well with a model of the body's balance control system we developed in the early 1990s. To bolster the model, we performed an analysis of our stabilograms that relied on the data's similarities to the random motions of microscopic particles. The analysis suggested that the body uses not one but two types of control systems while standing. If it drifts off center for less than a second or for a small distance, the nervous system appears to be using an open-loop control system -- that is, one that does not use sensory feedback to keep it on target. But over longer time periods and greater distances, a closed-loop, feedback-driven system appears to kick in and help the body right itself.
In the vibrating sole experiments, we performed the same analysis, which showed that people's balance control systems seemed to be more tightly controlled when under the influence of noise. That is, when the insoles were vibrating, they swayed a shorter distance before feedback control helped correct their posture. Since we know that the vibrations enhance the sense of touch on the foot, the point at which the body switches to feedback-based control appears to be influenced by the sensitivity of mechanical sensors in the feet.
na denn:
gibts denn ein "Audiophiles Rauschen" ?
im prinzip - ja. wenn man nix davon hört !
wenn man es hört, ist es eben rauschen - und das ist störend, nichts anderes.
ein Audiophiles Rauschen ist aber möglich, sofern der pegel so gering ist, dass es nicht (!!!) als rauschen wahrgenommen wird
-> erklärung: jeder sensor, also auch unsere ohren, hat eine minimale schwelle, unterhalb der keine wahrnehmung erfolgt. wird nun zu einem solchen -eigentlich- zu kleinen sigal ein rauschen etwa gleicher grösse addiert , wird eine wahrnehmung möglich.
diese methode wird technisch auch dithering genannt und zb bei A/D-wandlern verwendet, um die auflösung im bereich des LSB zu verbessern bzw zu linearisieren.
im home-audio-bereich ist zusätzliches rauschen allerdings bei richtiger abhör-lautstärke völlig sinnlos, da alle tonträger bereits mehr als genug davon enthalten ! wird im studio bereits zt absichtlich, zt unabsichtlich dem signal hinzugefügt.
im home-audio-bereich kann also der effekt einer verbesserung der auflösung nur dann mit zusätzlichem rauschen möglich sein, wenn die abhör-lautstärke so gering ist, dass das ohnehin zb auf cd enthaltene rauschen deutlich unter der auflösung der (schlechten) home-anlage liegt. der zum signal hinzugefügte rauschanteil darf aber nicht als rauschen hörbar werden, sonst wird die auflösung wieder verschlechtert.
hoffe, dass das hiermit mal geklärt ist...
dazu noch ein beispiel:
verbesserung der empfindung an den fuss-sohlen durch zusätzliche vibration mit rausch-signal
quelle: http://www.spectrum.ieee.org/geek-life/p...cing-act/2
To prove that someone's sense of touch could be improved, we had to first find that person's sensory limits. Clinicians routinely do this by poking patients with either a standard kit of filaments of different stiffnesses or a vibrating probe. Finding the level at which the patient feels the force of the filament or the vibration of the probe quantifies that patient's sensitivity. By recording a person's performance while randomly switching the stimulation on and off, we can show whether the noise boosts sensitivity.
In experiments we performed in collaboration with Aristidis Veves at the Joslin-Beth Israel Deaconess Foot Center, in Boston, we showed that we could improve sensitivity on foot soles of people with diabetes through the use of vibrating insoles. The vibrations were so small that the patients could not feel them, removing any chance that they would be biased in favor of the noise.
These findings complement earlier work by our group showing that imperceptible random vibration could enhance sensitivity on the fingers of the young, the elderly, and stroke patients, as well as those with diabetes. Future research will focus on the ability of diabetic subjects wearing vibrating insoles to improve their gait and walking patterns to minimize uneven pressure points.
We've gone a step further, so to speak, from just measuring sensitivity in our work with older people. Here we are looking at how a little noise can help them stay on their feet. We hypothesized that a heightened sense of touch on the soles of the feet can be integrated into the sensory-motor control system that allows people to maintain their balance while standing still.
We asked test subjects to stand on a pair of vibrating insoles, with their eyes closed [see illustration, " Still Standing"]. We set the amplitude of the vibrational noise to a low level and then slowly increased it until the research subject could feel it. (This level is different for each person.) Then we dialed down the amount of noise until it was just under that level, which effectively blinds the subject as to whether the stimulation is on or off during the trials. We put a reflective marker on the subject's shoulder and tracked its horizontal position with a special camera system. In an attempt to quantify the subject's balance from his or her posture, we plotted the shoulder marker's movements while the noise was turned on and when it was off.
The result, called a stabilogram, is an incomplete measure of how stable the subjects were when standing -- there are too many joints between the shoulder and the feet to fully analyze posture from it. Nevertheless, the movement at the shoulder can tell us important things, such as how much a person sways before the internal control system makes a correction. In general, a tightening of the stabilogram indicates greater stability.
We performed the experiments with people in their 20s as well as people in their 70s, and we demonstrated a significant improvement in balance control in both groups when noisy vibration was applied to the soles of the feet. In particular, we found that both young and old subjects swayed considerably less when the vibrating insoles were turned on.
The improvement was more pronounced for the older group -- so much so that when the septuagenarians wore the vibrating insoles, they swayed similarly to the twenty-somethings without vibrations.
Our results also fit well with a model of the body's balance control system we developed in the early 1990s. To bolster the model, we performed an analysis of our stabilograms that relied on the data's similarities to the random motions of microscopic particles. The analysis suggested that the body uses not one but two types of control systems while standing. If it drifts off center for less than a second or for a small distance, the nervous system appears to be using an open-loop control system -- that is, one that does not use sensory feedback to keep it on target. But over longer time periods and greater distances, a closed-loop, feedback-driven system appears to kick in and help the body right itself.
In the vibrating sole experiments, we performed the same analysis, which showed that people's balance control systems seemed to be more tightly controlled when under the influence of noise. That is, when the insoles were vibrating, they swayed a shorter distance before feedback control helped correct their posture. Since we know that the vibrations enhance the sense of touch on the foot, the point at which the body switches to feedback-based control appears to be influenced by the sensitivity of mechanical sensors in the feet.
Don't worry about getting older. You're still gonna do dump stuff...only slower