Objective Sound and Psychoacoustics Viers on Location Sound

Objective Sound and Psychoacoustics

Viers on Location Sound Gathering production sound Nat, b-roll, interview, dialog “Technique will trump technology” (pg. 2) Audience shouldn't notice sound; should be immersive Sound mixer (recordist): gathers sound on set “If it sounds bad on set, it will sound bad in post” (p. 2) ENG, EFP, and feature

Viers on SFX “Know the tools, so you can break the rules” Dialogue, music, SFX (simulation of “event”) 5 Types of effects Hard effects: sound/picture association (punch) Foley: perform sounds with picture (footsteps) Background/BG: ambience/atmos (room tone, city) Electronic SFX/Production Elements Sound design effects: unnaturally recorded sound

Sound Propagation / Psychoacoutics 1) Sound is generated and “objective” world acts on it 2) That world is then represented in our “subjective” mind (pyschoacoustics. . . study of sound perception) Remember. . . we are both scientists and artists!!! Practice hearing. . . practice listening!!! Learn to hear visually (image, and what sound) To to visualize sonically (sound, and what image)

Sound is. . . Changes in atmospheric pressure Vibrations Acoustic energy Produces a moving sound wave (propagation)

Sound Waves Sound decreases over distance; loss of energy Sound waves travel to our ears; our ears are an instrument!!! Can travel through matter: air, water, solid Slowest through the air! Sound is absorbed (weakened) through matter Sound travels slower than light Reality is out of sync

Compression/Rarefaction • Compression: upward movement, tight air molecules • Rarefaction: downward movement, loose molecules • Wave cycle: full comp/rarefaction

Measuring Sound: Frequency • Number of complete wave cycles in one second – Think of as vibrations per second • Measured in hertz (Hz) • A sound with 100 cycles per second=100 Hz; 1000 per second 1 KHz • We hear/feel frequency as low (bass), mids, and highs (treble) • Associate frequency (objective) with pitch (sub)

Frequency Cont'd Highs (5 KHz-20 KHz): perceived as louder, weaker, thinner, seems to travel faster; close distance to source of sound Lows (20 Hz-200 Hz): felt before heard, hear through solids (walls), greater distance from source we hear bass Human hearing range= 20 Hz to 20 KHz But, response is 40 Hz-18 KHz Women can hear better than men!!!

Measuring Sound: Amplitude aka LEVEL (sound energy) is interpreted by our ears as volume SPL= loudness of sound compared to silence (0 d. B) Ear has 140 d. B of dynamic range; 85 d. B SPL for monitors Amplitude is measured in decibels (d. B)

Signal Measurement How sound is measure on analog/digital devices (recorders, software, mixers, etc). Difference between measuring SPL of sound in d. B and signal d. B 0 db on most digital meters is the ceiling=clipping +3 d. B=double power; +6 d. B= double volume; -6 d. B=half the volume Line/mic level

Sound v. Audio • Sound is ACOUSTIC energy • Audio is acoustic energy that is TRANSDUCED into ELECTRICAL energy through? ? ? • Audio is the analog/digital representation of sound

Acoustics • Sonic characteristics of space and the study thereof. . . clap in a room! • Acoustic guitars, theaters, etc. work as “amplifiers” • Recording and Foley studios seek to be acoustically “dead” to not alter sound • Acoustics affect how we hear • Acoustics affect how we record and what is recorded

Reverberation Sound is movement through matter When sound hits surfaces it is reflected (reverberated) and will continue to reflect until it loses all energy Reverb creates an “echo” Sound reverberates off of opposite surface Concrete creates tons of reverb; wood absorbs it well; foam/cork/fabric absorbs it better; blankies Avoid reverb in recording; ADD in post

Noise • Airborne noise • Structure-borne

Phase Cancellation • Record a sound event w/ 2 mics or mix two sounds (usually one track) – Creates slight delay that puts them out of phase • Same amplitude and same frequency between to signals will fully or partially cancel each other out • If record both mics signals onto two tracks you can fix in • If in phase, the two signals will increase the amplitude