QUIZ 2 Flashcards
what are the 3 elements of acoustics
sound, ambience, music
the sensation stimulated in the organs of hearing by mechanical radiant energy transmitted as longitudinal pressure waves through the air or other medium vibration in an elastic medium
sound
the type of sound that is considered to be desirable
?
a measure of the acoustics energy emitted from a noise source, expressed in decibels
sound power
the power carried by sound waves per unit area in a direction perpendicular to that area
sound intensity
the unit of the sound pressure level
pascal
a longitudinal pressure wave in air or elastic medium esp. one producing an audible sensation
sound wave
the no. of times the cycle of compression and rarefaction of air occurs in a given unit of time
frequency
transmission of sound is primarily retarded by the barrier’s ____ & ____
mass & stiffness
the log ratio of the incident energy to the transmitted energy
sound transmission energy
a score given to a building’s surface based on it ability to reduce sound coming through it
sound transmission class
an STC rating that is considered to have a very poor performance that even low speech is audible
20-25db
an STC rating that is considered have good performance where loud speech heard is hardly understood
35-40db
an NRC rating of ___ absorbs all sound
1
an NRC rating of ___ absorbs no sound
0
the passage of sound from one room to another or from the exterior into a room in a building
sound transmission
used to evaluate the sound absorption efficiency of materials. It is the ratio of absorbed energy to incident energy and is represented by a.
sound absorption coefficient
give 3 kinds of sound absorbers
porous, membrane & resonance
the change of direction that a ray of sound undergoes when it strikes a surface
sound reflection
defines the refraction angle corresponding to the transmitted waves
snell’s law
whereby a sound wave moves around an object whose dimensions are smaller that or about equal to the wavelength of the sound
sound diffraction
the persistence of sound after it has been stopped due to multiple reflections from surface such as furniture, people, air etc. within a closed surface
sound reverberation
the repetition of sound cause by reflection of sound waves from a hard surface back to the listener
sound echo
an acoustical defect occurs if there are two parallel reflecting walls
flutter echo
result of the sound foci which causes the sound intensity in certain areas to be so low that is its already insufficient for hearing
dead spots
