~Chapter 12 - Lecture Section 12.2 Flashcards
Our perception of sound quality is influenced by the ___, and much of it can be attributed to ___ vs ___ sounds.
environment // indirect // direct
What are Direct Sounds?
Sound waves reaching your ear traveling straight from the source
What are Indirect Sounds?
Sound waves reaching your ear later, after they have bounced off other objects
The outdoors are mostly ___ sounds, whilst indoors has more ___ sounds.
direct // indirect
Even though ___ sounds reach our ears from many different directions, they usually don’t affect ___.
indirect // sound localization
Indirect sounds still affect our perception of ___, but the time it takes for the reflected sounds to reach the ears is usually too long, and we end up treating it slightly different than the ___.
sound quality // ITD’s
If sound is coming from the lag and the lead speaker simultaneously, there will be fusion, and they’re gonna perceive the sound as coming from the ___, because there is ___ IDT.
center // 0
If there is a very slight delay between 0.1-1ms, with the lead (R) speaker stimulating first followed by the lag (L) speaker, the subject will perceive the sound as coming slightly to the ___ on the Azimuth, because the lead speaker is activated first.
right //
With a longer delay from the lag (L) speaker of 1-5ms, there is the ___, where all of the sound is attributed as coming from the ___ speaker. In other words, ITD is too ___, and all localization info is assigned to the extreme range.
precedence affect // lead // long
If the delay from the lag (L) is longer than 5ms, then the two sounds are perceived ___, such that, the second sound is perceived as an ___.
separately // echo
Longer time means a ___ Echo Threshold.
higher
When the delay between ___ and ___ sound exceeds a certain time we start to hear an ___
direct // indirect // echo
For brief clicks, the Echo threshold is ___.
5ms
You can have a longer difference/Echo Threshold if between the lead and the lag, if the lag speaker is ___. This occurs naturally in the environment because indirect sounds lose some of their sound energy to the walls as the sound is bouncing off of the walls.
slightly quieter
Indirect sounds are usually ___ than direct sounds.
quieter
The Echo Threshold is longer for sounds with ___ durations, such as ___ and ___, and that has to have very ___ differences between the lead and lag speaker to be perceived as echoing.
long // speech // music // long
What are Architectural Acoustics?
Architectural Acoustics is the study of how sound is reflected in rooms. Provides a practical application for auditory psychophysics.
What is our perception of sound and our enjoyment of live music depend on?
- The sound that is produced at the source
2. How sounds are reflected by the environment before they reach our ears
Acoustic Engineers are mostly concerned with the ___.
Particularly the auditory ___ of live music.
perception of music // quality
Certain concert halls give the ___ impression of “good acoustics”, such as the Symphony Hall in ___ and the Concertgebouw in ___.
subjective // Boston // Amsterdam
If there is lots of absorption, there is going to be ___ reflected sound waves, and ___ indirect sound
very few // very little
If there is little absorption, there’s going to be ___ reflected sound waves, and a ___ amount of indirect sound, this is a recipe for making something very echoey.
many // large
The room ___ affects how long it takes indirect sounds to reach the listener
size
If you have a ___, the indirect sounds don’t have to travel very far.
small room
If you have a very large hall, sometimes the sound wave goes a very long distance and takes a very long time to get back, and so there will be a ___ between the direct and indirect sound.
very large delay
The room shape affects the ___ that sound waves are reflected towards.
direction
In a room where there is reflection of sounds away from the audience, that will emphasize ___, but there can also be very undesirable patterns of constructive and destructive interference if the room is shaped in an ___ way.
direct sounds // odd
The New York Philharmonic Hall was built in 1962 with “optimal” reverberation time of ___. The entire interior was destroyed and rebuilt in 1992.
2s //
What do Acoustic Engineers use to characterize the mix of direct and indirect sounds?
Reverberation time, Intimacy ratio, Bass ratio, and Spaciousness factor
