User:FluffyDunlop/Essay/1echap
.1 Chapter one
My research focuses on what possibilities sonology & impulse response can offer for the development of sculptures, and how they can give a different awareness of places and spaces. My sculptures will give the viewer an object to look at. And make the viewer aware of their presence in the sculpture and space. Through this sculpture a different awareness of spaces and their acoustics properties is created.
Impulse response. The idea behind an Impulse Response (IR for short) is that a frequency sweep is played in a certain space. A frequency sweep is a sweep at a constant decibel level ranging from low frequencies to high frequencies. With using this method we are sure that every possible frequency is played in that space and it will give us a clear dataset of the reflective properties of that space.
An example if this method is the famous experiment I’m sitting in a room (1969) by composer Alvin Lucier. By recording a sentence spoken by Lucier and playing it back multiple times within a room. Lucier captured the acoustic properties in that room like an IR. After playing back and recording this sentence multiple times a garbled recording is left with vague sounds that contain only frequencies that reflect the best within that room.
My IR setup works the same but is only played once. The frequency sweep is played back in a space and is recorded through a microphone. The recording is put through a convolution algorithm where the acoustic data is captured and calculated. What happens through this process is that the original sound is “deducted” from the recorded sound, what are left is the frequencies that amplify or extinguish themselves within that particular space. The IR method has many appliances. In my own practice I use the IR method to give certain sound or dialogue a reverberant character. Imagine a sound score that consist of sounds recorded in “dry” rooms that have no reflection. These sounds are like blank canvases that can be enhanced by applying a reverb process. These reverbs that I use are all produced through IR processes. These reverb characteristics can put “dry” dialogue in a car “environment” through the use of impulse responses.
The aim within my project lies in the experience of the viewer. The idea is that a viewer experiences a certain space in a different then normal way. The impulse technique helps in the measurement of a certain space. The information that I get from the IR measurement is transformed in a physical object. For an audio specialist the wave shape can be deducted from the sculpture.
With this information a shape is deducted from raising and falling frequencies, just like in a statics graph. The line represents rising and falling frequencies; this line is then rotated around its own axis to create a 360-degree object. This object is the most important outcome of the measurement, and is therefore the representable image of the space the measurement was take in.
The Object. This object derived from the precise measurement is now the focus of the project. This object should have to properties of explaining itself with little context and still be objective to the viewer. The sculpture that came out of this research is quite a “classic” sculpture, comparable with artist such as Starck and Brian Wilshire.
My view on the sculpture is that the sculpture itself “reveals” the origin of the form and the material represents the presence of the viewer. The material is a direct link to the material the sculpture originated from, so with my first work a jar was the space where the Ir was taken en the sculpture is made out of glass. For the second sculpture I’m using an aluminum can as a space for the measurement, therefore the material of the second sculpture should be aluminum. One
My research focuses on the possibilities that sonology & computer models can offer for the development of sculptures (2d or 3d) and give a different awareness of places and spaces. It will give the viewer an object to look at and perceive the room in a different way. The way the room is visualised is trough the use of reflecting sound frequencies. This idea comes from a method, called impulse response. It is a method that I frequently use in my sound design practice. With the information that the impulse response gives, a sculpture is created to visualize the acoustic properties of that space.
The sculpture will be calculated and constructed in a 3d model by a computer and could be made in a physical object. The way the transition of a 3d model to a physical one is conceived needs to be determent, there are more ways of doing this and the size of the sculptures has a huge role in this.
The outcome of this research will be presented in the exposition gallery. The form of the presentation could be pictures, sculptures or both
The research starts in two directions that need to be one in the end. The first direction is the place or space and the second is the method of visualisation. What I found in my prototyping research stage is that you can't finish one direction without another. So it is important to develop them both and see where the different directions merge.
First sketches of the Impulse Response Setup
3D Mockup of the impulse response
With this project I’m aiming to surprise the viewer with a new perception of a space, and to connect the viewer to the space in a different way. The idea of engaging the viewer with the space comes from the idea that there are acoustics properties that you might not be aware of. Through this properties of a space I can visualize my research and let the viewer be engaged and connect to the space in different way
Within the early presentations of my proposal to my peers and pzw staff, I found out that the subject of impulse response is hard to grab. So the engagement with the viewer has some other aspects than just "presenting" objects or visualizations. I could choose to educate in the case that the impulse response technique plays a more narrative role. Or I could choose to leave the technical explanation out, this in case that the work is strong enough and doesn't need any technical details to explain the work. What I need to tell in a technical aspect is defined by the outcome of my research.
The idea of engaging the viewer with the space comes from the idea that there are acoustics properties that you might not be aware of. Through this properties of a space I can visualize my research and let the viewer be engaged and connect to the space in different way
An impulse response is a method to calculate the reverberant properties of a certain space. Trough the playback and recording of frequencies ranging from 0hz to 50kHz the resonating properties and thus the reverberant character of the space is calculated. Imagine a space where at one end speakers are placed and on the other end a microphone. Trough the speakers every usable sound frequency is played back and simultaneously recorded through the microphone. The signal that has been recorded through the microphone is now very important, because it contains every frequency that we've played back and all the reflections of the room that came within the recording. If we let the computer subtract the original frequencies from the recorded frequencies trough a convolution method, we are left with the Impulse Response of that room
Below are the basic sound examples of a Impulse Response technique.
A clean sweep to play - [A sine sweep from 20Hz to 20kHz]
A sine sweep from 20Hz to 20kHz recorded trough a microphone in a room - File:R1.ogg
Impulse Response through deconvolution method - File:Jar Response.ogg
These pictures show a representation of an impulse response. The way in witch the impulse response is shown is called a waterfall diagram.
Waterfall diagram of a Impulse response from a kitchen (measured in dB and Frequency)
Waterfall diagram of a Impulse response from an auditorium (measured in dB and Frequency)
The use of impulse response technique is one that I use daily in my work as a sound designer. Either to merge instruments together in a musical composition
or to use within sound for picture applications, like recreation of rooms, microphones and telephone systems or to be applied to automatic dialogue recording to fit a scene better. With my daily use of impulse responses I can say I'm quit familiar with them and the technique.
I started by setting up speakers in a 90 degree order with a microphone in between. This system, if mirrored and pointed to the opposite side of the room, can provide me with 4 impulse responses (1 for each speaker repeated once)
Initial setup
I found out that when I put the outcome of these four measurements trough my visualization workflow, that the amount of measurements was not enough to give a detailed model of the room. So I quickly abandoned my 2 speaker setup with 4 measurements. And went for a single speaker setup with 8 measurements. More work to get the angle of the speaker right but much more information due to more measurements. The distance of the microphone to the speaker is equal to all measurements and gave some weird mic placements within the measurement technique. I decided to leave the room in the way as I found it and to not mess around with furniture between measurements.
Second setup
Measurement 5 gave me some interesting microphone placement
Keeping equal distance
These are the recordings and the 8 measurements of that particular space (room 2.9 wdka)
Measurement 1
Measurement 2
Measurement 3
Measurement 4
Measurement 5
Measurement 6
Measurement 7
Measurement 8
From here the visualization research started. I looked at different ways to get a detailed curve out of the wave files, and the best way that worked for me was to import the audio in After Effects and apply the Wave Form filter to a solid and link the filter to my measurements. This gave me a tweak able visualization, where I could change the amount of points, lines, height and offset of the audio file. After I exported a Tiff image with the waveform, I imported the image in Adobe Illustrator to trace the image into a spline. With the spline of each measurement (8 total) I created a sphere like object in autodesk maya. This method if done with only 4 measurements gives a less detailed object to work with, this was the main reason to go from 4 measurements to 8.
Splines as exported from Illustrator
Splines imported into Autodesk Maya and shaped in a spherical setup
The gaps between the splines are now filled and the visualization is complete
Founding.
First thing that I found out is that a multiple speaker setup is quite hard to do, and makes thing unnecessary complex. The best way is to stick with multiple measurements trough the placement of 1 speaker and 1 microphone. I have measured on a horizontal level. After experiencing the horizontal method I question it may also be a good idea to go in height directions, moving the speakers up and directing outwards in a 360 degrees spherical angle.
The moment the wave form is analysed with the After Effects method, the measurements will loose the 1:1 accuracy. From here on out the model is not scientific accurate anymore. How This influences my research and what it does to the project I have yet to determine.
Next Step.
With the first prototype made in a 3d shape, the next step is to put this model into the physical world. For my other prototype I have been experimenting with visualising impulse response through 3e printing (see below)
I could do the same and find out what kind of shape I'll get. Some questions came out the feedback session and it seems good to research them:
What role the location of the measurement has in the project?
How can I connect the object to lets say a room and what does it mean?
Could similar sounds like impulse responses been made on a certain place?
During the tryouts with the above method, I experimented with different spaces and setups. One that worked well and had interesting results was the impulse response from a glass jar.
The jar was placed under a microphone and a speaker was placed inside the jar. One measurement was take and visualised through the same process as above. Through the 3d process a flower like object was generated.
With the nature of the sound in mind and the flower like shape that was developed through the process, I decided to print the object in 3d and put it back in its "origin".
Glass Jar with speaker
Print process
Final Product
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Bibliography:
Research
Impulse Response as explained by AudioEase
Sound Design by David Sonnenschein
Audio Check Test Tones
Similair Work
Driessen & Verstappen Solid Spaces
Technical Tools
Maya 3d software
Paper Mockup Software Pepakura