02 - Sound Field Configuration Flashcards
Name 3 factors that influence the calibration of sound levels
- size and shape of room
- absorbency/reflectance of room
- unwanted room noise
- distance between loudspeakers and listener
- direction of loudspeakers
- whether the listener is stationary or moving
- type of signal being used
What is “azimuth”
Refers to the direction of something with reference to the listener
- measured in degrees
- 0 degrees azimuth means the listener is facing the source; 90 degrees means the source is directly right of the listener
What are “room modes”?
The acoustic resonances (standing waves) in a room caused by parallel surfaces
- the dimensional resonance of a room where the distance between walls equals half the wavelength of the lowest resonant frequency, and resonates at all harmonic frequencies above it
- results in louder and quieter spots
What kinds of room characteristics increase the number of room modes?
- hard, reflective walls
- parallel walls
- square rooms
- cyclical sounds from a loudspeaker (allowing the same signal to add over and over)
What are the 3 sound fields in a reverberant room?
Direct/near Field
Free Field
Reverberant/Diffuse Field
What is the Inverse Square Law?
SPL falls by 6 dB for every doubling of the distance in the direct field
True or False: Unless the sound’s path is obstructed by an object, it radiates outward from the point source in concentric circles
True
_______ (high/low) frequencies are more directional
High
If anechoic chambers are best for Sound Field Audiometry, why don’t we use them?
Too Expensive
While testing in the diffuse field, the subject should be ____ meter(s) away from the speaker(s), and >0.6 meters away from the walls
1 meter
