Talk:Psychoacoustics
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It'd be nice to see a blurb about how this replies to digital audio technology, specifically in how the MP3 format utilizes psychoacoustics to remove aspects of sound that are not crucial to the perception of the sound. Just a blurb, though. I'm curious, and I think it'd make the article seem more relevant to a lot of people.
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[edit] Content from 'Field of Psychoacoustics'
I append, from page redirected here. Charles Matthews 09:49, 6 May 2004 (UTC)
[edit] Background
I removed the following because it is gibberish: "Sound is a continuous analog signal which, assuming infinitely small air molecules, can theoretically contain an infinite amount of information, thus being an infinite number of frequencies, each containing both magnitude and phase information." If you would like to include words to the effect of the deleted sentence, please reword them from airy-fairy to something that actually has meaning, humanities majors need not apply. As far as I am aware, molecules are finite physical particles with finite quantifiable properties. Theoretically Wikipedia and this article do not in fact exist and the keyboard is typing me, and to an extent Newton would have agreed, but it's rather pointless to sully an otherwise useful article with humanities nonsense. Perhaps if it really needs to be stated one could add a footnote with the referencing article - way down the bottom, it's simply too irrelevent and self-indulgent to place in the introduction.
[edit] 2^(12/12)
For the following:
When the fundamental frequency of a note (or tone) is multiplied by 2^(1/12), the result is the frequency of the next higher semitone. Going 12 notes higher (an octave) is the same as multiplying the frequency by 2^(12/12), which is the same as doubling the frequency.
Someone changed the 2^(12/12) to 2^(1/12). This is incorrect as (2^(1/12))^12 is 2^(12/12) which is 2^1, which would be the same as doubling.
[edit]
Psychoacoustics
Psychoacoustics can be defined simply as the psychological study of hearing. The aim of psychoacoustic research is to find out how hearing works. In other words, the aim is to discover how sounds entering the ear are processed by the ear and the brain in order to give the listener useful information about the world outside.
Psychoacoustics is not concerned with how sounds produce a particular emotional or cognitive response. We leave these aspects to the cognitive psychologists and stick to the basics. Having said that, psychoacoustics is a very broad area, and while there is a large overlap with physiology at one end, at the other end we sometimes appeal to mainstream psychology in order to account for our more complex experimental results.
Note:This definition has been taken from this page: http://privatewww.essex.ac.uk/~cplack/Psycho.html For more information you can look this page.
Related subjects: Another interesting page where this term is well explained is Chris Plack earpage: http://privatewww.essex.ac.uk/~cplack/welcome.html
[edit] Magnitude resolution
Frequency resolution is about 2 Hz in the mid range? Around what frequency? How about magnitude resolution? Someone said somewhere we can only hear 3 dB of difference, but I know from experience that it is better than that. Anyone have some better numbers? - Omegatron 19:57, May 20, 2004 (UTC)
- I can hear 1dB diff- just about- by listening hard. But 3 db is what most people can easily notice. Try it with Cool Edit or some other sound package on your computer/ Maybe people can hear less than 1 db diff with training.--Light current 05:54, 16 March 2006 (UTC)
[edit] Telephone bandwidth
"Should this have said 50Hz to 3500Hz? 500 seems incredibly high; it means the A above middle C is too low a note to be transmitted by a telephone, since that A is 440 Hz."
400 to 3400, says howstuffworks and one other random site. seems fine to me. - Omegatron 21:54, Jun 17, 2004 (UTC)
- While the fundamental frequency of middle C (or the A above it) might be too low for transmission, its harmonics wouldn't be -- which is presumably the reason why it is mentioned along with auditory illusions such as phantom fundamentals. A2's fundamental at 440Hz might not be reproduced at the receiver, but the the fundamental would nevertheless be sensed by the listener. -- Tlotoxl 01:43, 18 Jun 2004 (UTC)
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- Put that in the article! :-) - Omegatron
A similar phenomenon occurs in music. I know of it only through rock music and the use of distortion (because the guitar effect known as "distortion" alters the harmonic series), however, I have heard of it mentioned in orchestra music. The phenomenon occurs like this: when a power chord is inverted (that is, the fifth is placed below the root) and played with a large about of distortion, a "phantom root" is percieved, an octave below the root which is actually played. I have also heard of this "phantom octave" being heard after hearing The President's Own band playing in a highly acoustically tuned room. Immediatly after the band cut off, the room itself was vibrating at an increadibly low pitch, according to a first-hand account. Scheater5
- It wouldnt be the room - it would be your ears\brain. --Light current 04:43, 12 March 2006 (UTC)
Perhaps, but I see no reason why the room couldn't vibrate sympathetically. In addition, the a room vibrating could be "felt," allowing it to be sensed at a much lower frequency than the human ear could detect. Scheater5 01:44, 13 March 2006 (UTC)
- Correct if room is big enough and the fundamental was being generated, but phantom fundamentals are all in the mind--Light current 01:46, 13 March 2006 (UTC)
That may have been true for the incident with the President's Own. However, the unplayed funtamental with the guitar power chords is actually produced. It's a phenomenon with the harmonic series, highlighted by high levels of gain associated with rock guitar. Scheater5 21:24, 15 March 2006 (UTC)
[edit] Branchlist template added -see talk
I've added a Wikipedia:Branchlist template using the Wikipedia:Root page concept. This page is a good demonstration of the need for such a concept, as it duplicates the content of Equal-loudness contour to some extent and does not indicate the presence of detailed pages on Fletcher-Munson curves or Robinson-Dadson curves. I hope you will agree it makes it easier to navigate around and get the whole picture. --Lindosland 11:19, 6 April 2006 (UTC)
[edit] Updated references to link to paper.
From a Google search, I found a PDF of the "Reproducing low-pitched signals through small loudspeakers" paper by Aarts, Larsen and Schobben, so I linked it from the reference that was already on this page. It's not the same publication, but it seems likely to be the same paper, or a revised version thereof. Should the reference be changed to cite the actual publication that I linked to? -- Deven 15:34, 16 August 2006 (UTC)
[edit] Perception of Low Frequencies
It's absolutely untrue that the lower limit of hearing is 20Hz. You can easily hear down to single digit frequencies, assuming sufficient SPL. This should be corrected... I'll find citable references.
Pitch is essentially Gestalt perception of oscillation or pulsation, and this is one thing that necessarily delimits the low end of our hearing. Why do we hear pitch at all? Because--in the case of pulsation--we are still processing one pulse while we are registering the next: they blur. There is a certain threshold below which they don't blur, although I suppose theoretically they still might for someone with a very slow rate of neural processing: Thirty-second notes at q=120 are equivalent to a pulse wave of 16cps. TheScotch 10:28, 10 December 2006 (UTC)
[edit] Pre-echo
Can someone knowledgeable on the subject turn the above article into something that is clearer to the non-specialist. Jackiespeel 16:59, 23 February 2007 (UTC)
[edit] Beat frequency
Quote: "Another side effect of the ear’s non linear logarithmic response is that sounds which appear on the ear drum in close spectral proximity produce phantom beat notes"
Isn't this just the "beat frequency" that one studies in physics, which is independent of how the human ear works? elpincha 17:24, 26 March 2007 (UTC)
