Thursday 25 November 2010

How does the shape of a bell affect the sound (tone)

For the Sound Elective group work presentation, my current interest relates to the the shape and thickness of bells. Bells are known throughout the world as a spiritual instrument and interestingly has no accruate origin or date it was invented with examples around the world from the Chinese dynasty to Western Europe. Despite this distance, the function of a bell within particular cultures was used as a religous/spiritual and even superstitius symbol.

Interesting article here regarding the history: http://www.handbells.org.au/history/genhist.htm

'In medieval times bells were steeped in superstition. This was probably because of their long association with religion. They were baptised, and once baptised had the power to ward off evil spells and spirits. Bells were hung in doorways to protect visitors and the visited from the evil spirits which always wait around the door awaiting the chance to slip inside. A visitor would ring the bell to drive the spirits away then pass inside - which is the likely origin of the present day doorbell!'

How bells make their sound is a complex but interesting subject. The discussion here is restricted to bells of typical 'western' profile, rather than those of the east which have a very different shape. Western bells are usually hit by an iron clapper at a point on the inside, near the bottom, or by an iron clock hammer at an equivalent point on the outside. This impact causes the bell to vibrate in a number of different ways or modes. Each mode can have a different frequency, intensity, attack and decay time, and can be characterised by 'stationary' points or nodes, both around the rim, and vertically up the bell.

Taylor 1980s (Using a Seiko Chromatic Tuner ST-747) Chromatic scale note is D


Gillett and Johnston 1920s (Using a Seiko Chromatic Tuner ST-747) Note is A


Mears 1850s (Using a Seiko Chromatic Tuner ST-747 at 440Hz) Chromatic scale note is F


Rudhall 1730s (Using a Seiko Chromatic Tuner ST-747 at 440Hz) Chromatic scale note is A


Eldridge 1670s (Using a Seiko Chromatic Tuner ST-747 at 440Hz) Chromatic scale note is D#


York Foundry 1500s (Using a Seiko Chromatic Tuner ST-747 at 440Hz) Chromatic scale note is A


London 1400s (Using a Seiko Chromatic Tuner ST-747 at 440Hz) Chromatic scale note is C#



I found this image on a blog and thought it was very interesting on:
how the shape of a guitar would affect the sound




Collin's Lab: DIY Cymatics


Cymatics, also known as modal phenomena, is the study of visible sound and vibration, typically on the surface of a plate, diaphragm, or membrane. Directly visualizing vibrations involves using sound to excite media often in the form of particles, pastes, and liquids.

Monday 22 November 2010

Editing in Sound Forge

Sound Forge



Garage Band


Audio-Visual Art

Oskar Fischinger was an abstract animator, filmmaker, and painter
One of the pioneers of interpreting sound and music through video was the German artist Oskar Fischinger. Influenced by abstract painters such as Wassily Kandinsky, Fischinger created animations of colourful abstract shapes creating what he called “visual music”.


Monday 15 November 2010

Science can be fun?!?!

Bottle Cap Microphone!!


Slinkies and Star Wars Sound Effects (good after 1:12)

Saturday 13 November 2010

sound object research

The smallest sound that a person can hear, known as the threshold of hearing,

acoustic wave propagation

A sound wave is a vibration that travels through the air and through
>objects. When a wave reaches a surface of an object, some of the wave is
>reflected and some passes through into the object. Normally, very little of
>the wave remains within the object for very long. When the wave vibrates at
>a rate natural to the object, much of the wave remains within the object.
>As more waves like this enter the object, vibration builds up enough to
>distort or break the object.
http://www.newton.dep.anl.gov/askasci/phy00/phy00092.htm
 
http://science.howstuffworks.com/humans-hear-in-space1.htm

http://www.hibberts.co.uk/tuning.htm

Thursday 11 November 2010

Cymatic experiment



Cymatics is the study of visible sound and vibration, Typically the surface of a plate,is vibrated,in a thin coating of paste, or liquid, regions of maximum and minimum displacement are made visible Different patterns emerge in the exitatory medium depending on the geometry of the plate and the driving frequency.

Sunday 7 November 2010

Types of Digital Audio Formats (compressed/uncompressed)

Other Factors when recording sound

Useful Video:

Understand the Cables Used in Audio Recording -- powered by eHow.com

listening and recording- seeing and hearing

An early sound recorder
model of Édouard-Léon Scott de Martinville's phonautograph.
The device consisted of a horn or barrel that focused sound waves onto a membrane to which a hog's bristle was attached, causing the bristle to move and enabling it to inscribe the sound onto a visual medium. Initially, the phonautograph made recordings onto a lamp-blackened glass plate. A later version (see image) used a medium of lamp-blackened paper on a drum or cylinder. Another version would draw a dotted line or wavy line representing the sound wave on a roll of paper. The phonautograph was a laboratory curiosity for the study of acoustics. It was used to determine the frequency of a given musical pitch and to study sound and speech; it was not understood at that time that the waveform recorded by the phonautograph contained enough information about the sound wave that a playback mechanism could be used to recreate that sound.from wikipedia


Sound Art created by recording of sounds:

Strange unexplained acoustics in Mexico?

Unexplained Acoustics

Taken from:- http://www.tomzap.com/sounds.html


At least two structures at the Mayan ruins of Chichen Itza in Mexican display unusual and unexplained acoustical properties.

taken from: 

The Great Ballcourt:

The Great Ballcourt is 545 feet long and 225 feet wide overall. It has no vault, no continuity between the walls and is totally open to the sky.
Each end has a raised "temple" area. A whisper from end can be heard clearly at the other end 500 feet away and through the length and breath of the court. The sound waves are unaffected by wind direction or time of day/night. Archaeologists engaged in the reconstruction noted that the sound transmission became stronger and clearer as they proceeded. In 1931 Leopold Stokowski spent 4 days at the site to determine the acoustic principals that could be applied to an open-air concert theater he was designing.
Stokowski failed to learn the secret.

taken from: 


The Castillo:

This structure is a temple that looks like a pyramid and is the one most commonly pictured on travel brochures for the Mexican Yucatan. Apparently if you stand facing the foot of the temple and shout the echo comes back as a piercing shriek. Also, a person standing on the top step can speak in a normal voice and be heard by those at ground level for some distance. This quality is also shared by another Mayan pyramid at Tikal.
I believe a good case can be made that the Maya somehow engineered these acoustical phenomena. After months of research, I cannot locate any scientific discussion or investigations regarding any of this. Any information or comments appreciated.

taken from: 




Friday 5 November 2010

Microphone Types

All information below provided by Paul White at  http://www.soundonsound.com/sos/apr98/articles/mic_types.html


MIC TYPES & CHARACTERISTICS

The type of mic you choose for a given task can have a profound effect on the quality of the resulting recording. 

THE DYNAMIC MIC

The live music market accounts for the majority of low-cost dynamic microphone sales (that's not counting the really cheap, nasty models inflicted on the domestic audio market), but a significant number of these mics also end up in home studios. By examining how this type of microphone differs from the 'perfect ear', it's easier to get a handle on what they might reasonably be expected to cope with.
"Dynamic mics are useful when the sound source is close and reasonably loud."
A typical budget dynamic mic has an upper frequency-response limit of around 16kHz, as opposed to the 20kHz or so of a good capacitor mic. The human hearing range is always quoted as extending up to 20kHz, even though few can actually match this. Subjectively, the result of this curtailed upper response for dynamic mics is that most of them don't do justice to very high-frequency sounds such as cymbals, bells, or the upper harmonics of the acoustic guitar or piano. They'll make a fair stab at the job for demo purposes, but if you compare the result to that achieved with a capacitor mic, you'll notice that a lot of the 'air' and transparency around the top end is missing.


CAPACITOR MICS

Capacitor microphones are the mainstay of professional recording and are characterised by high sensitivity and a good high-frequency response. Though a capacitor mic can tackle any job that a dynamic model can, dynamic models still tend to be used for bass drum and tom recording because of their physical strength (drummers are notoriously bad shots!), and because of their good mid-range punch. However, some engineers use capacitor mics for drum-kit recording where a more natural sound is required -- in jazz recording, for example.
Studio vocals are generally recorded with capacitor mics, though some rock singers like to use their dynamic models to give them a more punchy, middly sound. Mick Jagger and Phil Collins are reputed to prefer recording via dynamic models, so even if you do have access to capacitor mics, try recording your vocals via your dynamic mics and compare the results. You might be surprised at which you prefer.

"Capacitor microphones are the mainstay of professional recording."

BACK-ELECTRET MICS

It's usual to see back-electret mics as the poor relations of the true capacitor microphone, but this is a largely unfair perception. The capsule construction of the back-electret mic is essentially the same as for the capacitor model, except that the charge for the capsule comes from a permanently charged electret material fixed to the capsule back-plate. Indeed, some of the best studio mics, such as those made by B&K, use back-electret capsules. However, the nature of a back-electret capsule means that it is generally considered impractical to build a multi-pattern model working on that principle. For that reason, all the back-electret mics I know of have a fixed polar pattern, or one that can be modified by acoustic means only to provide differing widths of cardioid pattern.



All Information  below is provided by: http://www.btinternet.com/~paformusic/mics.htm

Omni-directional or Uni-directional
  • Omni-directional mics pick up sound with equal sensitivity from all directions. This is not normally useful for PA work, because in PA work each mic is targetted at a single sound source (so that the amplification given to that sound can be controlled separately from others, and so that pick-up of unwanted sounds can be minimised). Their application is generally limited to recording work (particularly of ambient sounds) and to sound-level measurement.
  • Uni-directional mics pick up sound with greater sensitivity from the front than from other directions. There are several variations on this theme. Each of the following types is illustrated with a polar response diagram, in which increased sensitivity in a particular direction is indicated by the line on the diagram being closer to the outer circle. Imagine the microphone diaphragm being located at the centre of the circle, with the most sensitive end (or side) of the microphone facing towards the top of the circle. So, the upper-most point of the line on each diagram indicates the sensitivity at the front of the microphone, or at '0 degrees' − i.e. the on-axis response, and the lower-most point indicates the sensitivity at the back, or at '180 degrees'. (The diagrams below are simplified to illustrate typical mid-frequency responses; in practice the polar responses vary with frequency, so check the manufacturer's specifications.)
    • Sub-cardioid mics have a very gradually reducing sensitivity from the front to the back, maintaining some sensitivity at the back.
    • Cardioid mics have a gradually reducing sensitivity from the front to the back, with very little sensitivity at the back.
    • Super-cardioid mics reduce their sensitivity from the front to the sides at a faster rate than cardioid types, reaching a minimum sensitivity at an angle of around 120-140°, measured from the front. The sensitivity then increases again towards the back, but the sensitivity at the back is still very much less than at the front.
    • Hyper-cardioid mics provide even less sensitivity at the sides than do super-cardioid types, at the expense of a little more sensitivity at the back. Therefore, a monitorspeaker should never be placed directly behind this type of mic. Their minimum sensitivity is at an angle of around 100-120°, measured from the front.
    • 'Rifle' or 'shotgun' mics are the most directional type, so-called because of their long rifle-like barrels. They are generally used only for long-distance miking (more than 2 metres from the source), e.g. for theatrical work, and should be located such that the back of the mic is not exposed to unwanted sounds.
  • Bi-directional types
    Although not featured in the title of this sub-section (as they are rarely used in live PA work), bi-directional mics get a mention here for completeness. They pick up sound with equal sensitivity from two opposite directions, shown in the diagram as the front and back; in practice however, as these are usuallyside-addressed types, the sensitive directions are most commonly on two of its sides.





GREAT SOUND!

WOW! I just caught a recording of a great sound of a rubbish collection van.  For me it sounded like anything but that!!  Maybe more like a large dinosaur giving birth!!!

1.  Rubbish collection


Let me know what you think?

Thursday 4 November 2010

Recording a Sound file

I borrowed a sound recorder and is my first time seeing a sound recorder with such a small microphone. it is small and easier to use unlike the ones I have used before that required a full microphone and large recording unit.

The model used was ICR-BI70NX
Sound Recording Device used (hired from Uni)










I started walking to station I recorded any sound I heard, because I was more continuous of sounds, they seemed different them usually.

The sounds I recorded were:

1. Walking on leaves,


2. Traffic and People


3. A girl on the phone


4. On the Bus


5. bus


6. Underground train arriving


7. doors in underground


8. Door


9. beep



In the end I decided that the Children was the most interesting as they all together sound interesting and abit like birds making noise.


Secret life of Camberwell
As a group we recorded sounds around college
1. elevator


2. In the shop


3. Workshop


4. Workshop


5. Coffee Machin


6. in the shop

Notes from Previous Research (October 15th 2010)

Difference between hearing and seeing, 


Interesting thoughts?

- Hearing is more unconscious, see is conscious?
- Hearing physically effects body more
- Sound makes your imagination work more
- Sound changes perception about reality
- Adding sound effects the perception about visual work more than vice versa
- Seeing is in colours, when sound can seem in different colours in each persons imagination
- Sound effects other senses in the body than visual/seeing only effects visual aspects?

Previous Notes (October 8th 2010)

How can sound be represented in visual form?

http://www.soundelective.wikidot.com/

Look for sound artists/sound poetry.

Sound can effect spirituality through connecting to eternity, ex. when sound goes for ever. (eternal being)

my visual interpretations of some every day sounds:

Breaking bones

Crunching

Oyster card beep

Kissing

Walking on snow

Sound Elective

This will be the blog for the remaining sound elective research.