Science topics: PsychologyPsychoacoustics
Science topic
Psychoacoustics - Science topic
Psychoacoustics are the science pertaining to the interrelationship of psychologic phenomena and the individual's response to the physical properties of sound.
Questions related to Psychoacoustics
Human binaural sound source localization is complex.
ITD (Interaural Time Differences) and ILD (Interaural Level Differences) are 2 main clues used by humans for binaural sound source localization, but other clues must be used to explain obtained results on experiments trying to evaluate human performance in binaural sound source localization, such as:
- performance difference between the setup where the sound source position/orientation is fixed and (1. the listener can voluntarily move its head) and (2. the listener is not allowed to move its head),
- performance difference between (1. individualized HRIRs) and (2. non-individualized HRIRs),
- performance difference between (1. BRIRs of anechoic rooms) and (2. BRIRs of semi-reverberant rooms)
- performance difference between (1. BRIRs recorded in a room and reproduced, with non-isolating headphones, in the same room) and (2. BRIRs recorded in a room and reproduced in another room which has different acoustic characteristics) (not sure about that, but it is my guess),
- etc.
I know that, biologically, human auditory system does
1) some kind of wavelet analysis, similarly to a CNN in Machine Learning, applied independantly to left and right ear signal, then
2) some kind of (left-right) multi-band temporal encoding (Spike Neural Network) and analysis (multiple delay lines + coincidence detectors), somehow similarly to a MLP with positional encoding in Machine Learning.
Because temporal information between left/right channels is required, I wonder why not much studies are using dirac impulses as sound stimuli, which have the interesting property of guaranteeing the non-distorsion (or destruction) of temporal clues ?
Why, instead of dirac sound stimuli, most of the experiments are based on other sound stimulis, such as short burst noises, human voices, or any other sound stimulis ?
In particular because in my opinion:
1) short burst noises doesn't preserve all -potentially useful- temporal clues (I think it only somehow preserves clues that would be based on signal amplitude envelope due to the short windowing of the stimuli....),
2) human voices or other sounds (if recorded in anechoic environment and with a unique mono-channel microphone) may preserve all temporal clues, but may not have full-spectrum energy.
Are there any technical reasons, except maybe the difficulty to produce a loud enough dirac impulse with headphones, that may justify the non-usage of dirac impulses as sound stimuli in binaural sound source localization experiments ?
Thank you very much !
Best regards,
Jean
When finding the detection threshold, is it easier or faster in any of the cases? Is there a difference in the steepness of the psychometric curve? In my case, I am looking at how different conditions influence the detection accuracy. I'm flexible in the choice of method.
Thanks!
Hello everyone,
I have been told in an informal discussion that some headphones can "have a strong Impact on the HRTF (directional sound incidence on the ear) even though they (averaged over all directions) only marginally influence the sound incidence (which is typically named acoustic transparent)."
I would like to know if there exists some evaluation about the influences that such "acoustic transparant" headphones may have, when weared but not used for sound reproduction, on the localization accuracy of a sound emitted by an external source.
Surely, I am also interested in all contents that may be closely related to this case.
Best regards,
Jean.
My thesis research is around acoustic ecology in a framework of critical design. I am curious to know in what ways I can create a time-based experience in a set space, which makes listeners explicitly aware of their slightest acoustic impact on the environment. What are the things I need to consider to “multiply” the psychoacoustic information to “play” it back via a sound system in order to “unsettle” the audience's sense perception(s)?
I am studying how different filter parameters affect the perception of timbre in synthetic vowels. I have been using a sawtooth signal, which is good a signal, but sounds a bit harsh and not quite 'organic' to my liking.
Can you suggest a better synthetic (reverse-filtered ?) alternative to the sawtooth wave for filter shaping?
I wonder if we can agree upon a certain voice source - and take it as a standard for synthetic vowel stimuli? That would be a step towards further parametrization of stimuli used in psychoacoustic study of vowels and timbre perception.
I am working on psychoacoustic active noise control. I want to design an psychoacoustic model for sound quality measurement. I went through the book of Zwicker's loudness: Psychoacoustic Facts and Models.
I am not able to understand how to write the program in matlab to calculate the loudness.
In perceptual listening tests, subjects have to listen to sound examples and rate their sound quality or other characteristics.
As these tests can be quite long, a serious and practically relevant question is if participants change their rating behaviour over time, maybe because the prolonged concentration while listening and rating leads to fatigue, or subjects adapt to the stimuli in some way.
Do you know of any studies or publications that treat this question, whether subjects rate stimuli differently depending on whether they're presented at the beginning of the test or at the end?
Cheers!
The future of Architectural Education.
Hi !
Can anybody point me at resources in which to explore possible (sound) frequency formulations to be administered as treatments ?
If the topic really interests you, please continue reading. Skip all that´s below otherwise... it´s loooooong :)
Some background to my research:
I am looking for all possible ways in which we might further harness the power of sound energy for health and transformation. And one is frequency (if you happen to know answers to my questions based on anything other than frequency please get in touch).
During the years, I´ve many times encountered the work of various reputed (although sometimes controversial) health professionals who understood frequency as one of the possible keys to health - starting way back with Rife in his attempt to control pathogens and followed by many others including Dr Alfred Tomatis who thought that sound is a nutrient to our nervous system.
Some more recent are Hans Georg Trzopek who through a system called Psychofonie® (akin to sonification ?), converts the beta/theta ratios - EEG biofeedback readings in locations C3, C4, T3, T4 - of an individual´s relaxed wake state (with eyes closed) into inharmonic sounds for adjunct headache relief treatments.
Of special interest is also Dr Paul Swingle and his work on Subthreshold harmonics as adjunct treatment for Neurofeedback interventions, which suggests there are two distinct mechanisms for conscious and subliminal sound detection, both of which can be effectively stimulated with sound energy in order to create measurable positive changes in mood, cognition, performance etc.
I´m also particularly interested in the work of Gubert Finsterle and his PAT sessions, currently being converted into a headphone-based system (they originally needed 4 special speakers placed at equal distance from the listener) that has been approved as medical device by the Italian Ministry of Health (he is also exploring the induction of specific neurotransmitters with sound).
Another contemporary figure is Sharry Edwards, somebody who is closer to the holographic model and pioneered the emerging field of vocal profiling (she calls her work "sonistry"). Her work is based on sound too, but perhaps closer to the field of Energy Medicine (a fascinating field - you might have heard of Dr Robert O. Becker, Dr William Tiller, Dr Josh Oschman, Donna Eden...)
In my view, the work of all these people (and those many others I have not mentioned or haven´t heard of yet) in one way or another suggests that there might be mathematical models "behind" what we call homeostasis (which affects much more than what can be seen or measured with our current instrumentation). If this is correct, "health" should be non-invasively programmable (hacked) with sound frequency formulations alone by some kind of "analogic principle" (analogy, transposition, transduction - sonostasis). In fact, energy medicine is somehow based on similar assumptions pertaining to procedures and orders of magnitude not yet accepted in mainstream circles. Taking into account how little consensus there is about it, frequency might not be the whole story, but given my research and experiential findings, surely a good start, with practical applications that are probably safer and cheaper than those we currently use (think sonoceutical industry !).
I imagine there must be some work done on finding the specific resonant frequencies of organs and tissues, as well as the frequencies that might somehow "trigger" self-healing responses, or support the immune system - Sharry Edwards proposes (among many other things) that low frequency sound presentation can be used to influence pathogenic activity within the blood. Other similar examples are infrasound technology, used with horses for treating pain, inflammation and swelling, and also for calming therapies. Or a field called audioanalgesia (developed in the late 50´s, I believe mainly for dental operations in which anesthesia could not be administered). There´s also fascinating work being done in the field of ultrasound. I know that Stuart Hameroff and his team are testing transcranial ultrasound (TUS) at megahertz and find it improves mood and may be useful in promoting neuronal growth via effects in microtubules.
I´m also intrigued by Cymatics (sound made visible) and wonder about the potential for certain "soundshapes" to be more life-affirming than others (in the context of healing). Some cymatic research suggests that sound might be made of holographic bubbles and by looking at the shapes single tones produce (called cymagliphs) one can easily picture what might be happening as sound reaches our bodies (specially water molecules inside us). I am also familiar with some more "esoteric" bodies of work related to the use of sound to stimulate the human energy system.
As part of my research, I have tried and tested various technologies based on most of what I´ve shared here, particularly varieties of what´s called "auditory driving" (or brainwave entrainment), but also other modalities using sound, light and subtle energy. Being a developer of such technologies myself, this field is of special interest to me and as a result, I am in conversations with some researchers I´ve found to be "jumping" around the various fields that this inquiry is weaved upon, but still, I would love to get some help !
Can you give me a hand in any ways ?
Perhaps you can:
- point me at relevant resources I an unaware of
(I haven´t included everything here, but what´s seems most relevant to my question)
- put me in contact with researchers who have similar interests to mine
- suggest places in which I might be able to conduct research that includes detection of various biomarkers such as EEG, galvanic skin response, HRV... etc (having access to other brain or body imaging techniques would be amazing too of course)
- join me ? !
Thank you so much for reading and for whatever you might contribute with (even if it´s only reading)
The stimulus level is decreased by a step of the same magnitude after three correct responses, not necessarily consecutive. The admission of nonconsecutive responses introduces a statistical problem. Statistical aspect depends on ratio between incorrect and correct responses. The probabilities of correct responses in a set of three non consecutive ones can be not constant. The 75% level of correct responses can be derived theoretically without referring to individual probabilities of correct responses. The derivation is based on proportions of correct and incorrect responses. The test period has to be sufficiently long to produce an approximately constant stimulus level.
Suppose I have y = conv (x,h) + n = s +n, where h is channel impulse response with length L and unnormalized. How do I define SNR? Is it SNR = power of x/power of n or SNR = power of s/power of n?
Dimensional personality models (also mood) were used in music emotion research by Jonna Vuoskoski et al. (http://users.ox.ac.uk/~musf0093/publications.html) - is someone extending this work to soundscapes? Soundscape research has used e.g. the Weinstein Noise Sensitivity index, however this describes a specific trait, and not an individual's personality as a whole. There are several models for assessing soundscape quality.
The wavelengths of the same frequency are substantially different in air and water. Do humans utilize wavelength in auditory pitch perception? This would also apply to rooms/places with substantially different air temperatures, and has implications for understanding auditory localization.
I'm looking for a paper that supports the idea that noise has detrimental effects on a person's performance in tasks that require concentration, e.g. social interaction, cognitive processes, or other motor and sensory effects.
