Auditory Neuroscience - Science topic

For the selection of frequency in case of rTMS for tinnitus it is necessary to stimulate the relevant cortex. If less frequency is selected it would not stimulate the specific cortex eg. Temporal lobe as because the relative thickness of the temporal bone is stimulated by frequency around 1Hz.

And if we set a higher frequency it would overstimulate the cortex. That will produce more tinnitus.

So traditionally 1Hz is used with a variable result. But research may be take place to reduce the variability in outcome whether this explanation is correct or not.

By embedding a tone in noise, you can reduce (unnecessary) effects of external and internal noise. There is always external noise in your measurement environment, and it is difficult to completely remove it. There is always internal noise, coming from inside a listener. You can control them by adding noise of sufficient intensity. In theory, the slope of psychometric function become shallower when the nose is added, since the slope reflects the noise variance.

To my best knowledge the answer is NO.

Auditory processing or just response to air vibration always requiere a step based in mechanorreceptors, and a mechano-electricla transduction process.

I don't have a clear answer for the BIC question. However, regarding the latter part of the question about existence of binaural neurons at different levels int he auditory system, have you seen the Jefress Model ?

Regarding the BIC, in the scalp recorded AEP, I have written a manuscript related to it. If you are interested, I can send it to you.

In threshold comparison method, the subject has to decide when he stopped hearing. This may not be accurate many of the times or it may become difficult to execute in old, too young or less co-operative subjects.

On the other hand, loudness comparison is more straight forward in comparing which one is louder; thats all.

So, I think, this may be the reason why loudness comparison method is better than threshold comparison method.

The knowledge of acoustics and mathematics is important for a musician.

Allow to know and explain a series of phenomena associated with the perception of the sound/music, musical performance and musical composition.

Depending on the type of musical composition, the mathematical knowledge can be associated to pure inspirations.

@ Stephen Politzer-Ahles  Thank you very much for great advice.

If you were able to find a database of English words in IPA and import that into SIL's Phonology Assistant program (https://www.sil.org/resources/software_fonts/phonology-assistant, its free) you could easily answer your question and also look at it from multiple angles. 

If you can't find a database in IPA, you could import the CMU corpus above, but you would have to define the phonological features of each of the graphemes and digraphemes. If would be a little bit of work, but not too much. You could then easily compare your results against a token frequency list such as found at (http://www.wordfrequency.info/)

It would help to know more about your equipment, e.g., whether your microphone system has a probe tube on it. In essence you want to put the microphone at the position of the eardrum, which can be done with a probe tube and an anesthetized animal. Otherwise measure with the microphone at the position where the animal's eardrum(s) will be during the procedure. You also need to be sure that you are using a free-field calibrated microphone. If you change the setup you need to re-check the calibration. Make sure the space around the animal is free of hard, sound-reflecting surfaces or cover such things with soft cloth.

i don't have the answer, just some tracks. Perhaps you should look at the works of Zilles' team in humans, like a staining some receptors or on myelin (weigert?) could work (primary auditory cortex is highly myelinated). From Moerel et al. (2014) : "Zilles et al. (2002)  mapped the human cortex based on multiple transmitter receptors (Zilles et al., 2002; Morosan et al., 2005). They found that human PAC contained a high density of cholinergic muscarinic M2 and nicotinic receptions, most densely expressed in middle cortical layers. Both M2 and nicotinic receptor density sharply dropped at the lateral border of PAC with the belt (Clarke and Morosan, 2012)."

Another track would be to look at studies working on the organization of auditory cortical fields in rodents, they should use some staining of interest for you.

Catherine Best, Catherine Stevens, Rick Van der Zwan (combines visual and auditory psychophysics). Just to name a few.

definitely it has effect on cells and also it matter what quantity of decibels (ultrasound waves can affect the growth of cells)

I use the following example in my teaching (mainly to demonstrate how awesome human hearing is): when you walk down a street and you hear the sound of (for example) an acoustic guitar being played (not too badly) you are generally able to hear whether someone is playing an actual guitar or playing back a recording of a guitar for the very reason Dr. Mannis suggests. Our psychoacoustic systems pick up so many precise directional cues that we can easily identify the predictable response of a loudspeaker in a certain acoustic condition (a park, a room with an open window etc). I imagine we might even be able to make out the difference between an electric guitar amplifier and a recording, taking the specific sound of such speakers in consideration.

Technically I assume you could analyse an experimental recording with a microphone array and look at the distribution of direction/frequency; if it's complex it's an instrument or a human or an animal (or a tree falling in a forrest) if it's relatively simply (i.e. all higher frequency in the same direction) it would likely be coming from a loudspeaker.

Would make a fun research project :-)

This is 2016. If it is important that you "experience" the environment and can't be there, at least be there virtually in both the auditory and visual domains. You can equip a manikin with microphones for binaural sound recording and with a camera for binocular video recording and then play them or stream them so that you can experience the environment for the duration of the recording or stream from the reference pointof the manikin. How tht would add to your learning about the environment would depend upon what you need to know. 

Mario,

In the firing for shorter time periods, the rate varies stochastically, even if an auditory fibre is phase locked to a high degree (perfect phase locking is not observed, but vector strengths can be very high, meaning that the vast majority of intervals are locked to the phase of the stimulus). So it really is a question of what you mean by constant. The most exact spacing in time is only achieved during phase locking to high-level sounds at low frequencies – that is frequencies below the maximum firing rate of the fibre. Above that frequency, some of the cycles of the stimulus will be “missed”, i.e. the fibre will not be able to fire again that quickly. However, the spacing of the next firing will still be closely related to the phase (one, two, three cycles, etc). There is no minimum firing rate of auditory neurons in the cochlea – all of them have spontaneous activity that can be from below 1 spike/s up to about 100/s. During phase locking, such spontaneous firings become “locked” to the sound stimulus. The maximum firing rate of primary auditory neurons is somewhat higher than 300/second, pretty much irrespective of the best-response sound frequency. This maximum rate is not restricted to the auditory system but is true for all neurons of endothermic vertebrates. The longer the sound pulse, the more the rate will fall over time, often reaching a lower plateau rate after about 50 -100 ms (this is called adaptation). As I wrote before, it is likely that at low frequencies, the brain uses the spacing of the firings to derive the frequency of the sound (originally called the “volley theory”). Above frequencies where the spacing between firings no longer contains this information, i.e., above perhaps 1-2 kHz in humans (this is a guess), the information concerning the frequency of the sound is only conveyed by the place of origin of the fibres in the cochlea (tonotopic organization). What a firing neuron sounds like (the one in this video has a very variable rate and is not, I think, an auditory neuron) can be heard at:

I am not aware of a web site that offers a real sound recording of cochlear neurons firing, but some firing patterns are shown, for example in:

Geoff Manley

Are there any fMRI studies on KKS?

For temporal rates: Christianson, Sahani and Linden J. Neurosci. 2011. For ripple density - tuning curves in rats and mice are typically wider than in ferrets, and I wouldn't expect the need to use denser ripples than in the ferret.

While the causes of Tullio phenomenon are diverse, I believe the commonest we encounter here in sub-saharan Africa is due to Superior canal dehiscience. I agree with Eduardo Martin-Sqnz that surgical options is only beneficial with large dehiscience.

This is an interesting question. I have been "involved" with this topic since the 1908s, thus my answer is somewhat long, and certainly reflects my personal opinion.  However, any answer to this question is not without controversy.

As noted above, the primary reason for using "dBnHL" is to account for the differences between behavioural thresholds at each frequency, so that "0 dBnHL" represents the median or mean threshold for normal adults. This is the same concept as "dB HL", which uses (nearly) continuous tones. As also noted above, however, in contrast with behavioural HL, even with the "nHL" correction, one still has to apply "eHL" correction factors reflecting  differences between AEP (usually ABR) thresholds and behavioural thresholds; correction factors which are different for infants compared to adults.

Unfortunately, it is not so simple as dBHL, because "dBnHL" has had to be calculated for so many different stimuli (e.g., clicks for ABR, 5-cycle brief tones for ABR, chirp stimuli for ABR or ASSR, 40-60-ms tones for corticals). Complicating this issue further is that different presentation rates are used -- behavioural thresholds change with rate (even though AEP, especially ABR, thresholds do not show such changes with rate). Finally, and very importantly, the physical calibration of non-continuous tones is a little more complicated; most clinicians and many researchers, and, indeed, many audiometric calibration technicians, do not know how to calibrate these stimuli.

My colleagues and I have been pretty adamant that individual clinics should not typically determine their own "nHL" values, as this requires large numbers of normal subjects, careful threshold procedures, and quiet test rooms. Rather, assuming they are using stimuli essentially identical to others' studies which investigated nHLs (or a "standard" such as the ISO standard), they should have their stimuli carefully calibrated acoustically to the previously published nHL calibration standard.

In our previous studies, we determined nHL calibrations for all stimuli using a 10/s stimulus rate, regardless of the actual rate used to record the AEP in the study (we did this because the ABR and MLR do not show better thresholds with increasing rates, whereas behavioural thresholds do). The ISO standard mentioned above by Stig Arlinger states that a 20/s rate should be used when determining nHL calibrations -- I am not sure why they selected 20/s, but the difference in threshold would be very small (only 1-2 dB) (Stapells et al., JASA, 1982).

The above confusing situation is made worse by the fact that there is not yet agreement as to formal RETSPLs/RETFLs (i.e., "standards")  even for the most commonly used stimuli for ABR testing. As Stig Arlinger has noted above, there is an ISO standard for brief stimuli, specifically clicks and brief-tone stimuli. However, these "standards" are not fully accepted, especially for tonal stimuli (e.g., they are not commonly used in North America). They tended to ignore or discredit substantial preceding research into nHL thresholds and, in the case of tonal nHLs, they have some significant differences. (Oddly, the reference force levels for bone conduction in these "standards" were estimated from pure-tone standards, rather than directly determined.) 

The move towards  "standard" reference thresholds is important, but it must also take into account previous research and consider differences. My greatest concern is that the large majority of research into adult and, importantly,  infant tone-ABR thresholds has been carried-out using nHL values that are different from the ISO standard -- any possible move to a different standard must consider how this relates to the results (and interpretation) of the past and future studies.

Problems will still remain even if a standard becomes widely accepted worldwide. Every time a new or different stimulus comes out (e.g., chirp stimuli), no standard will exist, and some sort of nHL needed.

Lately, I have wondered if we should never have moved to developing "nHL". Rather, perhaps we should have just used well-established pure-tone "HL" calibrations, and then determined what are the normal ABR (or MLR or ASSR) offsets/corrections. (This would eliminate problems with calibration, but would still entail questions with determining the offsets/corrections.) This is essentially what most researchers carrying out threshold assessments using the ASSR or CAEP (cortical auditory evoked potential) have resorted to.

Given the current situation, although not all would agree with me, I recommend one use the nHL calibrations from the study(ies) one is trying to emulate. For example, if you are testing infant ABR thresholds using the stimuli and parameters I have recommended, then you would use the nHL calibrations I have published. On the other had, if you are using Michael Gorga's stimuli and parameters, then use his published calibrations. I expect, with time, there will be more movement towards use of standard reference thresholds as we understand/explain current differences.

Hello Jenn - You can search for keywords like "entrainment" or "groove".

You will find references to a large body of research in the following (very recent: November 2014) paper:

Burger, B., Thompson, M. R., Luck, G., Saarikallio, S. H., & Toiviainen, P. (2014). Hunting for the beat in the body: on period and phase locking in music-induced movement. Frontiers in Human Neuroscience, 8. doi:10.3389/fnhum.2014.00903

It is downloadable here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4224089/

Best, Olivier

please go to the research of Rick van Dijk in Plos one: Haptic spatial configuration in Deaf and Hearing individuals (april 2013)Full tekst on line\and from the same author: Superir touch : improved haptic orientation preocessing in deaf individuals. Experimetnal brain research October 2013

You don't need to use an invasive technique to extract CSF. It can be done easily from the cisterna magna at the base of the skull. Check out this video: https://www.youtube.com/watch?v=45hq3oatvy4

Music is present in all cultures since prehistoric times, but still it is not clear what the source of gratification that we feel listening. Two newly published studies now contribute to shed light on the brain mechanisms involved in the joy of music.

As you can read in "Science", Valorie N. Salimpoor and colleagues at the Montreal Neurological Institute of McGill University have analyzed the neural processes of volunteers who listened to the first few songs. To give way to the experimenters to assess the degree of pleasure evoked by the music, the subjects participated in a kind of auction in which they could make an offer to listen to a particular song.

"Viewing the activity of a particular brain area, the nucleus accumbens, which is involved in reward, it was possible to reliably predict whether subjects would have offered money to listen to a song," says Salimpoor. The involvement of the nucleus accumbens confirms recent indications of the fact that the emotional effect of music would activate mechanisms of expectation and anticipation of a stimulus desirable, mediated by the neurotransmitter dopamine when it comes to a song already familiar, the mechanism of leave would be evoked mental anticipation of the passages most enjoyable. In the search for Salimpoor colleagues, however, the music was not known, but functional magnetic resonance imaging showed that the activated areas and dopaminergic mediation were the same as those of well-known songs. The cause, according to the researchers, is an "implicit knowledge" of music, obtained over the years and internalize the structure of the music characteristic of a certain culture.

The activity of the nucleus accumbens, also, is not isolated, but also involves the auditory cortex, which stores information on the sounds and the music during the test, as the piece was rewarding, the more intense was the cross-communication between the different brain regions. This result supports the idea that the ability to appreciate music refers not only to the emotional aspects, but also on assessments of cognitive character.

Still on the subject of brain reactions to music, Vinod Menon and colleagues at Stanford University School of Medicine, authors of an article published in the "European Journal of Neuroscience," have shown that listening to classical music evokes a unique pattern of activation of areas of the brain in spite of the differences between people.

The team recorded the activation of different brain regions of volunteers who listened to the music of William Boyce, an English composer of the eighteenth century, or pieces of "pseudo-music", ie sequences of auditory stimuli obtained by altering the songs Boyce with appropriate algorithms by the computer. The reaserchers identified a distributed network of brain structures whose activity levels followed a similar pattern in all subjects while listening to music, but not in that of the pseudo-music.

"In our study we have shown for the first time that, despite individual differences, classical music evokes in subjects other than one very consistent pattern of activity in various structures of the frontoparietal cortex, including those involved in the planning of movement, memory and attention, "says Menon. These regions, in particular, participated each with its own activation rate to the development of what was being heard, helping to make sense, with its own specific contribution to the overall structure of the music.

Particularly curious is the preferential activation of the centers of motor planning in response to the music but not the pseudo-music: according to the authors, it is a "neural correlate" of the spontaneous tendency to accompany listening to music with body movements, as in the dance, or simply clapping his hands.

I red with particular interest these two papers which well summarize the mucic/brain interaction. And let me understand what is happening when I am listening to a favourite music. I do not know whether similar mechanisms are activated when I enjoy to  write, play and sing my songs. Many of you know that this is one of my hobbies.

Change pitch perception by will? Yes! Try this: turn on a sinewave generator, then bite your teeth quite hard together. The loudness changes, and (likely due to that), the perceived pitch. You can also shake your head to create a nice pitch-vibrato (Doppler effect).

It is very difficult to get commercially available linear hearing aids. Phonak still offers a limited number but the stock dates back many years. Their current product line along with Siemens, Oticon, Widex, Starkey, Unitron and Bernafon do not include a linear hearing aid. Some hearing aids can be programmed to be linear in gain, Starkey and Siemens and Phonak but sound cleaning tools will still be active.

personally I like

"Hearing Instrument Technology for the Hearing Health Care Professional by Andi Vonlanthen and Horst Arndt" as a very good overview of hearing aid technology and fitting strategies. However if you are looking at the different fitting strategies, i also suggest you read the how they were derived. I have been less than impressed by the methodology utilized by some.

The only thing I found is the influence of radii ratio: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2299218/

It's really interesting, but as human's cochlear doesn't vary in radii ratio that much, this should be neglectable.

Daniel,

The bird system is simply a delay line. As the conduction speed of signals in nerves is low, much lower than the speed of electric signals in cables, a series of coincidence detectors as illustrated in the figure can code for interaural delay. The neurons in the delay line will only fire if a signal arrives at the same time from both ears, an by making the nerve fibre from one ear longer than the finbre from the other ear, the cell will fire at a preferred delay. Each coincidence detecting neuron has its own tuning curve (sinusoidal curves in b) and so cover the entire range of interaural delays.

In mammals, all delay-sensitive neurons are tuned with maximum sensitivity to delays outside the maximal possible delay between the ears and the interaural delay is thus directly coded in the level of response (straight part of curve in the purple part of the figure in d).

Coincidentally, the leading expert on this (and author of the paper) Benedict Grothe, happens to sit right across town from you!

Best regards

Jakob

I think the search terms you are looking for are "Granular Synthesis". You should find a lot of software to produce sounds for bioacoustics using this technique.

I've seen people listening to verbose music sing along during a work day and go about task mindlessly...this music may be good for work that is chorish as opposed to detailed and mentally demanding.

I prefer classical which can by lyrical, melodic, emotional, and a whole spectrum of depth. I find it helps with stress and change the pace of the work I do.

I think listening to music gives people a sense of more control of their environments, where we are no longer surrounded by the banter of others or the noises of our worlds. We are more disconnected with the reality of the proximal area and more connected with the dilution of introspection. OR just using it as beat to work to.

Much of the music has lost its sense of creativity and now thrives on the momentarily catchiness of a meme. Much of the more creative music thrives on memes but they compliment it with tempo and volume irregularities. So, which music we see catching on more may signify whether or not we are more impulsive or contemplative.

I am biased in my views but I'd love to see studies looking into patterns of behavior and musical preference. Are your more rebellious listening to Rage against the Machine, Bob Marley, etc or do they listen to Top 40, or classical? Is there a difference between those that lead and those that follow and those that organize? There is going to be a great deal of personal bias,but as recently done, musical preference can be correlated to SAT scores (http://musicthatmakesyoudumb.virgil.gr/)