مقدمة لتصميم الصوت

مقدمة لتصميم الصوت
مطور النشاط	,|x|مطور::x}}
نبذة عنك	BSc in audio engineering and music production, attended special courses just for sound theory and synthesis. Very wide interest in this idea of creating sounds that for the last four years I have been working with synthesizers only, I even produced my whole album using only synthesizers.
نوع النشاط	,|x|نوع نشاط::x}}
مجال النشاط	في مجال::موسيقى وصوت
ملخص النشاط	ورشة عمل تتمحور حول أساسيات الصوت وكيفية إنشائه, كيفية تركيب عناصره والفوائد من برمجته.
أهداف النشاط	الهدف من هذه الورشة هو تعرف المشاركين على الطرق المختلفة اللتي يمكن من خلالها التلاعب بالصوت وخلقه.
المخرجات	فهم الصوت بشكل عام وأساسيات تصميمه وتركيبه.
وسائل إيضاح

مقدمة لتصميم الصوت
الفئة العمرية من	حد أدنى لفئة عمرية::16
الفئة العمرية إلى	حد أقصى لفئة عمرية::100
خلفية المشاركين	يجب أن يكون لدى المشاركين معرفة أساسية في الرياضيات, الفيزياء, اللغة الإنجليزية, وكيفية إستخدام الكمبيتر.
العدد الأدنى للمشاركين	حد أدنى لمشاركين::4
عدد أقصى للمشاركين	حد أقصى لمشاركين::9
طبيعة الدعوة	طبيعة دعوة::عامّة

مقدمة لتصميم الصوت
من	تاريخ::2013/12/07 00:00:01 PM
حتى	تاريخ::2013/12/07 00:00:07 PM

مقدمة لتصميم الصوت
من	تاريخ::
حتى	تاريخ::

مقدمة لتصميم الصوت
من	تاريخ::
حتى	تاريخ::

جلسة مقدمة لتصميم الصوت
مكان التنفيذ	,|x|ميزة مكان::x}}
الإنجازات	,|x|x}}
المعدات	,|x|أداة::x}}
خامات	,|x|خامة::x}}
مطبوعات	,|X|20px|thumb|X}}
وسائل إيضاح	وسيلة إيضاح::

تحضير ما قبل الجلسة

Print papers for the participants. Install pure data on all computers and make sure that the synthesizer is running

الخطوات التفصيلية للجلسة

-Class introduction

- introduction to sound: What is sound? Basically, sound consists of changes in air pressure that your ears capture which can be generated by any moving object. Sound waves have different intensities which we perceive as loudness, thats why when a sound is too loud you can actually feel it in your body. The speed of that waveform is interpreted as frequency or pitch, human beings can hear in the range of 20 Hz to 20,000 Hz, every hertz is one cycle of a waveform, one trip back and forth. A single Hertz can easily be produced by waving your hand back and forth, and it doesn't appear as sound since our ears can't "go that low". It does however generate a movement of air that you can easily feel. If you were able to wave your hand faster, at more than 20 back-and-forths per second, it would start sounding like a very deep bass tone.

time: 30 mins

- Introduction to sound synthesis: Sound synthesis is creating and shaping sounds. Let's think about it this way, we need to create a sound that means we need to move an object, the simplest thing we can move is a speaker by sending electrical signals which makes the cone move creating sound. A microphone is kind of a reversed speaker if you think of it, when you talk into a microphone you are moving the diaphragm inside it sending an electrical signal either to a platform or back to the speakers that makes them move and generate sound again. There are other ways of generating sound, you can use an analog synthesizer or a computer. A synthesizer creates sound from scratch using electronic devices, a computer creates sound using binary numbers (0, 1), that means you can actually give a computer numbers and it would generate sound. These ideas take us out of the bounds of what we hear everyday, they allows us to create sounds that have never been heard before.

So what we know by now is that when we talk into a microphone we vibrate the air then the microphone converts these vibrations into voltages or electrical signals. Now for these electrical signals to go onto our digital platform (computer) they go through a process called analog to digital conversion (ADC) which converts these signals into binary numbers. And logically when you re-play that sound, the binary numbers change back to electrical signals by a digital to analog convertor (DAC), this process is done by something called a sound card. In binary codes the 0 means rest, which is silence, and the 1 moves the cone in the speaker generating sound, now each one of these zeroes and ones is called a sample. Usually the sampling rate is 44,100 samples per second, we can say 44100Hz or 44.1KHz. Let me explain sampling a bit so you can visualize this process, a computer tries to recreate the waveform or redraw it by learning its shape. Here is a sine wave and its length is exactly one second, now in a system where our sampling rate is 44,100, that means the computer learns 44100 point in this wave form, it connects the points and recreates the waveform. Lets imagine that the sampling rate was much less, the waveform will not be created as it is perfectly, there will be parts missing which means that the sound will not be generated as it is. volume is measured between 0 and the peak displacement, either 1 or -1. peak to peak amplitude is called range, the wavelength is the measure between the closest two points with the same displacement moving in the same direction.The period (T) is the time it takes a wave to go through its rest point and come back again to that same point, this is measured in seconds. Now the number of times a period passes in a second is the frequency(f), so basically f=1/T Hz. Phhase is when two waves overlap, that might cause the waves to act as constructive or destructive waves. if two waves are exactly similar and completely off phase by 180 degrees it causes the sound to disappear, if they were in phase it doubles up the volume.

Let's concentrate a bit on frequency to understand harmonics, the middle A on a piano has a frequency of 440 Hz so logically the A overtone of it has a frequency of 880. now the middle B has a frequency of 440(12√2)^2 => the frequency of any note = middle A frequency (440) * (12√2)^note difference => it was 2 between A and B because there is the A# between them too. This idea is important just to understand how deep synthesis can go but I will give you a table that shows you the frequencies of every note incase you feel like experimenting. Now, all musical tones have complex waveforms made up of many different frequencies, all sounds are made up of a combination of sine waves at different frequencies and amplitudes. This is the job of a synthesizer, it generates sine waves and combines them together in many different ways. From a physical standpoint, the simplest waveform is the sine wave, it has no harmonics so it is considered as a pure sound. There are other simple waveforms that are used sometimes and they can all be created from a sine wave as well. There are square, pulse, sawtooth, triangle and noise waves. The square and triangle waves contain only odd harmonics while the rest contain all harmonics, noise has a random mix of all frequencies instead of actual tones. time: 1 hour

- synthesis types: There are many different synthesis techniques used to create complex sounds. there is additive synthesis which is adding waves to each other creating more complex waves than a sine wave. For instance when you create a saw, square, triangle, or pulse waves you are using additive synthesis because you are adding harmonics. You can create a sawtooth wave by placing the fundamental frequency, the pure tone, and adding to it the odd and even ordered harmonics. For a square wave, you place the fundamental and add odd harmonics, now for the triangle you add the odd harmonics and reduce the amplitude of each successive one. I'm not going to go in the math of that but later on we'll create a complex waveform from a sine wave to show you the idea behind all this. Now the thing that generates sound in a synthesizer is called an oscillator, we usually use more than one oscillator to create a complex sound. Everything that happens over time can have an envelope, an envelope is basically the shape. You can have separate envelopes for the amplitude, the pitch, the oscillators and the filters all running at the same time, so you are basically shaping everything that is happening. An envelope has four components, the attack time which controls the time it takes for the strike to hit or a note to play from the time it was pressed, the decay time how fast the sound goes down from the peak of the attack to the sustain level where it keeps on playing, the sustain is the level that the sound remains at after the decay and before the key is released, and finally the release time is the time it takes the sound to fade out after the key is released.

Another technique to synthesizing sounds is subtractive synthesis, which is basically subtracting waves from each other. You can look at it as a sculptor, he takes a block of rock and starts taking parts out of it in order to create his art. Subtractive synthesis revolves around filtering out frequencies from a rich full sound in order to create a tone. There are many different filters that can be used, the main ones are Low Pass Filter (LPF), High Pass Filter (HPF) and band pass filter (BPF). LPF cuts the high frequency and allows only the low to pass, HPF cuts the low and allows the high to pass and BPF, takes a range in the middle and cuts whatever is higher and lower. A main technique in controlling sound is modulation, it requires a modulator that controls the carrier, modulated, signal. You can modulate oscillators, amplitudes and frequencies creating many different sound effects. The envelope that we discussed before can be counted as a modulator, for instance when a filter's cut-off frequency is being modulated by an envelope it is like raising and lowering its frequency; when the envelope opens the sound is brighter and when it closes it seems darker. There is another modulator, the main modulator in synthesizers, and it is called a Low Frequency Oscillator (LFO). An LFO generates a really low and big waveform, usually between 0.1 and 10.0 Hz, that controls a parameter without generating actual sound, it kind of gives its shape to create the envelope of the parameter. in an LFO you can choose between a sine, saw, triangle and square waves, you can control the speed of the oscillations (rate) and perhaps a time delay before the oscillator starts. Using an LFO on the oscillator pitch would create a wobble.

FM synthesis creates the most complex sounds, it uses one oscillator as the main oscillator and uses the other oscillators to modulate the first one. Subtractive synthesis is like a salad, it is a combination of vegetables but you can recognize its separate elements, but FM synthesis is like baking the cake, the sum of its ingredients creates something that has nothing to do with them. There is also granular synthesis where you take a recorded sound, splice it into small grains that are maximum 50 milliseconds long and you take each grain of that, change its characteristics, shuffle them and play them back creating obscure unknown textures of sounds that depend completely on randomness. There are many other techniques but I'm not going to talk about them, I am only trying to give you a hint of how further synthesis can go but lets stick to these ideas and go on to the practical side of things. time: 1 hour

LONG LUNCH BREAK

explain how to use the custom built pure data synthesizer and its parameters: time: 30 minutes

create examples from the theoretical part: create complex waveforms from sinewave (saw, pulse, triangle, square, noise) create a vibrato, trill and alarm siren effects using LFO~MOD~OSC.PITCH create tremolo effect using LFO~MOD~AMPLIFIER time: 1 hour

record sounds, analyzing and remaking them time: 1 hour

ملاحظات (قبل و/أو بعد الجلسة)

If there are participants that have their own laptop and can bring it then we can have more people in the workshop

جلسة مقدمة لتصميم الصوت
مكان التنفيذ	,|x|ميزة مكان::x}}
الإنجازات	,|x|x}}
المعدات	,|x|أداة::x}}
خامات	,|x|خامة::x}}
مطبوعات	,|X|20px|thumb|X}}
وسائل إيضاح	وسيلة إيضاح::

ملاحظات (قبل و/أو بعد الجلسة)

جلسة مقدمة لتصميم الصوت
مكان التنفيذ	,|x|ميزة مكان::x}}
الإنجازات	,|x|x}}
المعدات	,|x|أداة::x}}
خامات	,|x|خامة::x}}
مطبوعات	,|X|20px|thumb|X}}
وسائل إيضاح	وسيلة إيضاح::

ملاحظات (قبل و/أو بعد الجلسة)

جلسة مقدمة لتصميم الصوت
مكان التنفيذ	,|x|ميزة مكان::x}}
الإنجازات	,|x|x}}
المعدات	,|x|أداة::x}}
خامات	,|x|خامة::x}}
مطبوعات	,|X|20px|thumb|X}}
وسائل إيضاح	وسيلة إيضاح::

ملاحظات (قبل و/أو بعد الجلسة)

تقييم النشاط
تقييم المشاركين للنشاط
مؤشرات نجاح أو فشل النشاط وإقتراحات لتطويره:
ملاحظات اخرى