for a complete beginner's intro to the fascinating world of neuroscience.
acoustics & signal processing
This is a little demo that we found described in the book "Vergleichende Tierphysiologie" by Neuweiler. It nicely illustrates that multiple harmonic components in a tone complex are usually "perceptually bound" and not individually perceived (unless you force them to "pop out"). The sounds in this demo are two simple "tone complexes". The first tone complex, let us call it tone A, comprises the first ten harmonics of 200 Hz (i.e. 200, 400, 600, ... , 2000 Hz and so on).
In the previous animation you have seen how a plucked guitar string will vibrate at numerous "modes of vibrarion" at once, and therefore produce sound at many harmonically related frequencies ("overtones"). Just to show that these modes of vibration are real, here a little youtube video by nicogetz, where he placed a camera phone inside his guitar and then played a tune.
As we age, our auditory sensitivity often declines, and the average decline is perhaps a lot more than you might think!
A little interactive demo to illustrate the role formants play in vowel sounds.
The fact that tone complexes with missing fundamentals can be perceived to have a pitch that is below their lowest frequency component can have counterintuitive consequences.
Consider the tone sequence shown in the spectrogram here:
This podcast by science journalist Dr Carinne Piekema explores how hearing loss affects people, in particular how it affects musicians, and what modern prosthetic devices such as hearing aids or cochlear implants can and cannot do for these patients. It contains insightful interviews with inspirational deaf musicians, some of the UKs leading hearing researchers, as well as simulations designed to show to normal listeners what it would be like to have to rely on a hearing aid or a cochlear implant.
You can listen to the podcast here,
Can this be done?
Is it possible to record the electrical brain pattern of a human in different states (walking, running, angry..etc..) and tranform these into sounds?
What would be the effects of playing this back to the subject?
I am considering this as my dissertation topic for my MSc, any ideas/ knowledge in this field are highly welcome!