The Acoustic Dimension

• Sound and Synchronization Technology Evolution

• Recording techniques / Perception

• Post-Production

• Presentation

What is sound

• Compressions and rarefactions of air pressure. • Transference of energy through a medium (air).

What is sound

• Energy propagates through a medium

Longitudinal Mechanical Wave

Wave propagating in air

Compressions and Rarefactions of air pressure

• Transceiver based. • For example: Air Pressure to Diaphragm

Wave propagating in air from a transmitter (e.g. a speaker) to a receiver (microphone diaphragm)

• Transceiver based. • Air Pressure to Diaphragm

Diaphragms can be an Ear Drum or a Microphone

Dynamic Microphone

Condencer Microphone

Human Ear

• Transceiver based. • Air Pressure to Diaphragm to electric current

to …

Sound wave moving a microphone diaphragm resulting in a fluctuating voltage.

Air Pressure to Diaphragm to electric current to digital encoding, and visa-versa

Fluctuating voltage is digitized by:

1. sample rate (48KHz) Horizontal Resolution

2. bit depth (16bit) Vertical Resolution

Digital Encoding of a Sound Wave

Fluctuating voltage is digitized by:

1. sample rate (48KHz) Horizontal Resolution

2. bit depth (16bit) Vertical Resolution

Perception of Sound

• Psychoacoustics – the study of the relationship between

physical sounds and the human perception of sound.

• The relationship between how our ear hears and how audio technology captures sound is not intuitive.

Perception of SoundPsychoacoustic Effects

• The Haas Effect (or precedence effect)

– An acoustic signal that arrives first at the ear suppresses the ability to hear other signals. ~40ms.

• The Cocktail Party Effect – The ability in perception to select one

desired sound from a background of ambient noise heard at the same time.

Elements of Sound Design

Element Perception

Diagetic Content

Ambience Context

Sound FX Verisimilitude

Music Emotion

Diffusion Spacialization / Localization