Apple is a great company giving many important details on how Siri is used.

For educational purposes here is an extract of the iOS 8.1 Licence Agreement:


"(c) Siri and Dictation. If your iOS Device supports Siri and Dictation, these features may allow you to make requests, give commands and dictate text to your device using your voice. When you use Siri or Dictation, the things you say will be recorded and sent to Apple in order to convert what you say into text and to process your requests. Your device will also send Apple other information, such as your name and nickname; the names, nicknames, and relationship with you (e.g., “my dad”) of your address book contacts; song names in your collection, and HomeKit-enabled devices in your home (e.g., “living room lights”) (collectively, your “User Data”). All of this data is used to help Siri and Dictation understand you better and recognize what you say. It is not linked to other data that Apple may have from your use of other Apple services. By using Siri or Dictation, you agree and consent to Apple’s and its subsidiaries’ and agents’ transmission, collection, maintenance, processing, and use of this information, including your voice input and User Data, to provide and improve Siri, Dictation, and dictation functionality in other Apple products and services. If you have Location Services turned on, the location of your iOS Device at the time you make a request to Siri may also be sent to Apple to help Siri improve the accuracy of its response to your location-based requests. You may disable the location-based functionality of Siri by going to the Location Services setting on your iOS Device and turning off the individual location setting for Siri. Siri can allow you to interact with your iOS Device without needing to unlock it. If you have enabled a passcode on your iOS Device and would like to prevent Siri from being used from the lock screen, you can tap Settings, tap General, tap Passcode Lock and turn the Siri option to “off”. You can also turn off Siri and Dictation altogether at any time. To do so, open Settings, tap General, tap Siri, and slide the Siri switch to “off”."


It is nice reading agreements and they are not too big. The English part is only 12 pages.
http://images.apple.com/legal/sla/docs/iOS81.pdf

Music is an Experiment of Beauty with the Human Brain

Buy Buy Interest Rate

Interest rate is clearly linked with energy reserves.


If you let money "grow" by interest rate soon it becomes so large that it is larger than the wealth of all earth!


Our only source of energy is the Sun which gives a certain amount of energy per day.


But for 100 years we could have millions of years of sun energy stored in oil under earth which we almost consumed between 1910-2010.


This allowed tremendous growth and interest rates.

On 2008 we have reached peak oil.


Why should Hellas that gave science, art and philosophy to the world pay for the energy that earth will now receive slowly in the next thousands of years?


So buy buy interest rate. Farewell. Be a good boy.

Octave Stretch by Ernst Terhardt

Octave stretch

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Since the days of Pythagoras (or even earlier) the musical octave interval has been associated with the ratio 1:2. Until the 17th Century, that ratio was essentially referring to the lengths of two strings with the same stress that give tones which are heard as being in the particular relationship of octave equivalence. In Galileo's days it became known that tones are periodic oscillations of air pressure and that the pitch of tones is determined by oscillation frequency. So the meaning of the 1:2 ratio was generalized, now referring to the frequency ratio of periodic tones of any origin. Understandably, in ancient days it was not possible to determine the ratio to an accuracy of, say, a few percent. So it was not possible to tell whether the ratio is precisely 1:2. Besides, hardly anyone cared - at least until the beginning of psychophysics in the second half of the 19th century. Stumpf (1890a) appears to have been the first to report on the observation that when the frequency of a tone is adjusted such that the auditory sense of octave equivalence is satisfied in comparison with a fixed preceding tone, the frequency ratio of the tones tends to be slightly greater than 2:1.

With simultaneous periodic tones it is easy to adjust them very accurately to a 2:1 frequency ratio just "by ear": When the frequencies differ ever so slightly from that ratio, beats are heard. Accurate tuning to 2:1 thus is merely a matter of making the beats as slow as possible, i.e., by adjusting either of the two frequencies appropriately. However, that kind of "octave adjustment" is in no respect dependent on the perception of pitch; little or nothing can be learned from it about the pitch interval that corresponds to octave-equivalent tones. With respect to music it is most interesting to know precisely the width of the pitch interval pertinent to auditory octave equivalence.

Measurement of that interval is easy enough. The listener is presented with a pair of alternating, i.e., successive tones of which one frequency is fixed, the other, variable. The listener adjusts the variable tone until optimal octave equivalence is obtained. This requires, of course, that listeners somehow are familiar with the music-psychological concept of "octave", and that they possess a built-in pitch-interval template of the octave interval to which the pitches of the test tones can be matched. This is more or less synonymous with saying that the auditory sense of octave equivalence is required to exist. As it turns out, this criterion indeed is met by the vast majority of individuals, i.e., not only in trained musicians but also in individuals who are musically inactive. Even in populations outside the Western musical culture existence of the sense for octave equivalence was verified (Burns & Ward 1982a).

Another requirement to do the above octave-adjustment experiment is sufficient accuracy of auditory short-term memory for pitch. This criterion in fact is met by the auditory system. High accuracy of short-term memory for pitch is a basic and universal feature of any normal auditory system. This is why successive tones can be adjusted to octave equivalence with a precision that is essentially identical to the accuracy to which the pitch of single tones can be measured. Octave adjustment with tone pairs that are two or more octaves apart, however, appears to require some musical experience and talent (Thurlow & Erchul 1977a).

The octave-adjustment experiment yields two frequencies, f₁, and f₂, which correspond to aurally estimated optimal octave equivalence. Formally, octave stretch - or, in a more general term, octave deviation - then is suitably defined by

W = (f2-2f1)/(2f1)

where f₁ < f₂ is presumed. Octave stretch is indicated by W > 0.

Depending on a number of parameters, values of W are obtained that, grossly, are in the range between 0 and a few percent (positive). It was shown by Walliser (1969b) that octave stretch is additive: When f₂ was obtained as corresponding to the octave of f₁, and f₄ was in another experiment obtained as corresponding to the octave of f₂, then a third experiment in which the listener adjusts f₄ relative to f₁ (i.e., spanning two octaves) yields a stretch that is the sum of those obtained in the first two single-octave tests.

Octave stretch with tones of musical instruments was described by Corso (1954b). The first comprehensive study of the phenomenon was carried out by Ward (1954a), who essentially used sine tones and determined octave deviations in a wide range of reference frequencies f₁. Though the data obtained in the latter study demonstrate that, grossly, there is a tendency for octave stretch, they also show that, in an individual ear of an individual listener, the octave deviation W may at particular frequencies as well be systematically negative. As a function of reference frequency, the octave deviation shows an oscillating pattern that is comparable to that found in binaural diplacusis (cf. van den Brink 1970a, [104] p. 338). The pattern is characteristic for any particular ear of any particular listener, and it is reproducible (van den Brink 1977a). It may thus be concluded that the gross tendency for octave stretch is superimposed by more effects, in particular, by the oscillating deviations of the ''frequency-to-pitch'' characteristic of an ear that can be indirectly deduced from measurements of binaural diplacusis (van den Brink 1977a, [100]).

Such systematic details of the frequency characteristic of W can occur only if the experiments are done with sine tones, and if the tones are presented monaurally. This is plausible, as the oscillating structure of that characteristic is different for each ear, such that it is averaged out when both ears are used at once. Therefore, in binaural octave adjustments with sine tones, and in monaural or binaural adjustments with harmonic complex tones, these details are not expected to occur, and they are in fact not found in the results of, e.g., Walliser (19969b), Sundberg & Lundqvist (1973a), Dobbins & Cuddy (1982a), [11]. What remains as a general effect is octave stretch. With harmonic complex tones, the octave stretch is generally smaller than with corresponding sine tones (Sundberg & Lindqvist 1973a, [11]).

The explanation of octave stretch virtually is included in the explanation of octave equivalence (see also topic affinity of tones). To explain the stretch of the octave one just has to take into account the phenomenon of pitch shifts. The key to explaining octave equivalence is the multiplicity of pitch of harmonic complex tones (see topic definition of pitch). Any harmonic complex tone evokes not only spectral pitches but also virtual pitches, of which the former occur above fundamental frequency, i.e. in harmonic positions, the latter below fundamental frequency, i.e. in subharmonic positions ([104] p. 313). Due to that kind of pitch multiplicity, harmonic complex tones whose oscillation frequencies are in a 1:2 ratio (or close to that) inevitably will have a number of pitches in common - which yields a kind of similarity. This is my explanation of octave equivalence. The explanation of octave stretch immediately follows from that, i.e., by taking into account that the intervals between the pitches of a harmonic complex tone must be expected to be stretched by pitch shifts. Due to this stretch of the pitch pattern, the best match of the two pitch patterns is obtained for an oscillation-frequency ratio that, on the average, somewhat exceeds the value 2:1 [86], [88], [93], [104] p. 197.

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Author: Ernst Terhardt Mar 10 2000

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Is the Pythagorian Comma a Pseudo Problem?

Pythagoras ahead of his time almost got it right because he was comparing string lengths. A half string vibrates more quickly than twice the frequency due to material stiffness.


Should he have an ipod touch with a signal generator he would be able to measure the frequency of the 2nd harmonic of pleasingly stretched sounded string to be a bit greater than x2!


Therefore the Pythagorean comma is a pseudo problem.


Tuning upwards from a given note by twelve intervals of 3/2 the final note will form an interval with the starting note which is sharper (the correct word here is higher) than the "octave" (mathematical octave, not what the human brain finds a satisfactory octave) by 23.5 cents (the Pythagorean comma).


This is a good thing since the ear likes to hear stretched octaves. (Even +23.5cents at such high frequency may sound flat! Easy to verify by any app like garagband to hear that a very high mathematical C sounds almost like B!)


Good sounding partials are not exact multiples anyway due to the same psycho acoustic reasons so it may well be that right sounding partials will automatically satisfy beat less stretched octaves. So no comma and no beats and at the same time great poetic sound. "Exact" x2 "octaves" sound appallingly flat. Corrected stretched by ear brain octaves and designed partial sound so beautiful they make us feel proud to be part of humanity and nature. Examples are a nicely tuned Steinway piano or a good orchestra with fine instruments and ear brain intonating players and conductors.

Attention to those who change from A440 Hz going below. The way pianos are scaled reducing tension to the strings may make the opposite and make 2nd partials flatter. trying at your own risk you can increase from 440Hz. If you do this on a guitar yes you can go below 440Hz but use thicker strings to keep string tension high if your guitar can stand it.

A Musical Work that Composes Itself?

An example can be the piece Prayer .


Violin 1 plays 1 bar less and repeats thus.


Violin 2 plays 2 bars less and repeats thus.


Viola plays 3 bars less and repeats thus etc.

Pleiades Microphone Preamplifier for iPad or ...

May need a source resistor of around 700 Ohms and a 47uf bypass capacitor to further adjust bass compensation response.