CA149 First Midterm Lecture Notes

John Cage

An influential composer known for his innovative works and exploration of sound possibilities.

Prepared Piano

A technique where objects are placed on or between piano strings to alter the sound.

4’33”

A composition by John Cage consisting of four minutes and thirty-three seconds of silence.

Geophony

Non-biological sounds in any given habitat, like wind or water.

Biophony

All sounds generated by organisms in a habitat at a specific time and place.

Anthrophony

Sounds generated by humans which can include music and environmental noise.

Soundscape Ecology

The study of sound within the environment, focusing on how sound operates within different habitats.

Psychoacoustics

The study of how humans perceive sound and its psychological effects.

Signal to Noise Ratio

The measure of the desired signal level compared to background noise in audio recording.

Decibel (dB)

A unit of measurement for sound intensity, quantifying the power level of an electrical signal.

Onomatopoeia

Words that phonetically imitate, resemble, or suggest the sound they describe.

Dynamic Range

The ratio between the largest and smallest values of a changeable quantity, often measured in audio levels.

Analog vs Digital Audio

Analog audio is continuous, while digital audio is represented in discrete values, minimizing degradation over time.

Microphone Transducer

A device that converts sound vibrations into electrical signals.

Classical Filters

Signal processing tools that restrict frequencies within certain bounds (low-pass, high-pass, bandpass).

Cymatics

The study of visible sound and vibration, demonstrating how sound affects matter.

Reverberation

The persistence of sound in a space after the source has stopped, caused by multiple reflections.

Absorption

The reduction of sound energy by materials within an environment that diminishes echoes.

Sampling

The process of taking a portion of audio and reusing it in a different context, prevalent in modern music.

Signal-to-Noise Ratio (SNR)

The ratio of the amplitude of the desired signal to the amplitude of background noise.

Dynamic Range

A measure of the quietest to loudest sounds a system can reproduce, measured in decibels (dB).

Sampling

The use of pre-recorded sounds in a new composition or context; can be recordings of instruments, voices, or environmental sounds.

Microphone

A device that converts acoustic energy (sound waves) into electrical energy (an audio signal).

Audio Filtering

The modification of an audio signal's frequency content using filters such as low-pass, high-pass, and band-pass filters.

Sound Absorption

The degree to which a material absorbs sound energy, preventing reflections and reducing reverberation.

Cymatics

The study of wave phenomena, exploring how sound vibrations create visible patterns on various mediums.

Soundscape

The collection of sounds characterizing a particular environment, encompassing geophony, biophony, and anthrophony.

John Cage

An influential composer known for his innovative works and exploration of sound possibilities.

Prepared Piano

A technique where objects are placed on or between piano strings to alter the sound.

4’33”

A composition by John Cage consisting of four minutes and thirty-three seconds of silence.

Geophony

Non-biological sounds in any given habitat, like wind or water.

Biophony

All sounds generated by organisms in a habitat at a specific time and place.

Anthrophony

Sounds generated by humans which can include music and environmental noise.

Soundscape Ecology

The study of sound within the environment, focusing on how sound operates within different habitats.

Psychoacoustics

The study of how humans perceive sound and its psychological effects.

Signal to Noise Ratio

The measure of the desired signal level compared to background noise in audio recording.

Decibel (dB)

A unit of measurement for sound intensity, quantifying the power level of an electrical signal.

Onomatopoeia

Words that phonetically imitate, resemble, or suggest the sound they describe.

Dynamic Range

The ratio between the largest and smallest values of a changeable quantity, often measured in audio levels.

Analog vs Digital Audio

Analog audio is continuous, while digital audio is represented in discrete values, minimizing degradation over time.

Microphone Transducer

A device that converts sound vibrations into electrical signals.

Classical Filters

Signal processing tools that restrict frequencies within certain bounds (low-pass, high-pass, bandpass).

Cymatics

The study of visible sound and vibration, demonstrating how sound affects matter.

Reverberation

The persistence of sound in a space after the source has stopped, caused by multiple reflections.

Absorption

The reduction of sound energy by materials within an environment that diminishes echoes.

Sampling

The process of taking a portion of audio and reusing it in a different context, prevalent in modern music.

Signal-to-Noise Ratio (SNR)

The ratio of the amplitude of the desired signal to the amplitude of background noise.

Dynamic Range

A measure of the quietest to loudest sounds a system can reproduce, measured in decibels (dB).

Sampling

The use of pre-recorded sounds in a new composition or context; can be recordings of instruments, voices, or environmental sounds.

Microphone

A device that converts acoustic energy (sound waves) into electrical energy (an audio signal).

Audio Filtering

The modification of an audio signal's frequency content using filters such as low-pass, high-pass, and band-pass filters.

Sound Absorption

The degree to which a material absorbs sound energy, preventing reflections and reducing reverberation.

Cymatics

The study of wave phenomena, exploring how sound vibrations create visible patterns on various mediums.

Soundscape

The collection of sounds characterizing a particular environment, encompassing geophony, biophony, and anthrophony.

Reverberation

Sound reflected so many times that no singular discontinuous repeat of the source is perceived; reflective surfaces are too close to listener to allow for subjectivity.

Echo

Sound source is distinctly reproduced; can be single or multiple.

Reverberation time

Time it takes for sound to die away to a level 60 dB below its original level.

Reflection (Sound Wave)

Hitting off surface in another direction; reflected sound almost as loud as incoming sound.

Absorption (Sound Wave)

Absorbing power determined by material used; some sound will travel through material instead of bouncing back.

Diffusion (Sound Wave)

Scatters sound off surface.

Low Frequency Sound

Large sound waves that move everywhere and can go around surfaces; nothing can really block it.

High Frequency Sound

More directional; don’t diffract as much; can’t wrap around objects the same way as low frequency.

Chamber Reverb

Put speaker in a very reverberant room (hard surfaced walls).

Spring Reverb

Put a mic next to springs; play sound through spring; vibrate spring.

Plate Reverb

Put a mic on plate; play sound through plate.

Digital Reverb

Done through technological system; done by math; control through how sound works.

Convolution Reverb

You make a whoosh, use math to multiply frequency of that sound with any other sound.

Roomsize (Reverb Parameter)

How soon early reflections of sound will come back to you.

Reverb Time (Parameter)

How long does sound actually bounce back and forth.

Damping (Reverb Parameter)

How much high frequency sound we lose.

Dry Signal Level (dB)

How much original sound you hear; works with tail level.

Tail Level (dB)

How much 'whoosh' from air you hear from tail; works with dry signal level.

Sound (Plato)

Anything that vibrates causes sound.

Harmonic Lyre (Stephen Ian McIntosh)

Octave of 7 tones; Orpheus’s lyre produced harmonies that joined all nature together; Pythagoras discovered sound vibrations using strings.

Harmony of the Spheres (Plato)

All spheres of the solar system create one large harmony, tying together music and science.

Cymatics

Pattern of sounds in liquids; demonstrates resonance.

Timbre

Quality of a sound that makes each voice sound different.

Low Pass Filter

Allows frequencies below a limit to pass.

High Pass Filter

Allows frequencies above a limit to pass.

Bandpass Filter

Filters frequencies between two limits.

Notch (Band-Reject) Filter

Passes all frequencies outside a range between two limits.

Frequencies

Walter Murch Quote:

“Music was the main poetic metaphor for that which could not be preserved”

Before recording, music only existed if you put a band to work; when finished, the moment was gone, never to be seen again. Recording captured and preserved music and sound.

Signal

Converting sound waves into a form that can be captured using a transducer. Useful forms include mechanical energy and voltage.

Signal to Noise Ratio

The ratio of the desired signal level compared to background noise in audio recording

Storage

Storage on a medium that allows a signal to be stored, such as magnetic tape, optical track, or digital encoding.

David Byrne Quote:

“Recording technology changed the way we hear. Neutral technology does not exist.”

You could replay something again capturing moments.

Phonautograph

Edouard-Leon Scott de Martinville's device that used a horn to collect sound waves and inscribe an image using a stiff bristle.

Magnetic Tape

Device used from WWII up to the 1990s to record; involves moving a transducer to generate an electrical signal and rearranging a magnetic field.

Overdubbing & Multitrack recording

Record multiple tracks which is useful for recording different instruments separately.

Non Linear Editing

Making edits in any order, usually done by software editing tools; (usually) non-destructive editing

Vibrato

oscillations above and below the pitch of a note, used to color a note.

Steps to audio production

Recording, Editing, Mixing, and Mastering

Recording

Set up mics, Record the sound (action)

Editing

Loading sounds, Cutting sounds, Preparing sounds, Sequencing sounds

Mixing (many tracks)

Mixing sounds over many tracks, Adjusting levels/pans, Introducing effects, Finalize track levels, Equalize audio between tracks

Mastering

Apply noise reduction, Adjust stereo width, Add local or global ambience, Add Reverb, Dynamic Expansion/Compression, Peak limit

Étude aux chemins de fer

Impression for its ability to recreate train sound very nicely.

Discreet Music - Brian Eno

Originally intended for Robert Fripp (guitar player) to use as background music.

Sampling beats

Classical composers take themes and reuse them to make other pieces from original pieces; creative act of reusing material.