Auditory Pattern Recognition

Question 1

Templates

Answer 1

• Outdated
  Language dont sound the same
  There are dialects
  Problem of invariance
• Matching with mental templates
  Use of pre-existing knowledge and memory

Question 2

Feature detection

Answer 2

• Succesful
  Problem of neglecting context

Question 3

Conceptual Driven processing

Answer 3

2 examples on why context matters
- Words at a part vs isolation
- Speech where one letter in a word is missing

Question 4

What happens when there is multiple, concurrent sounds?

Answer 4

• What should we focus on?
  Cocktail party problem
• Segregating different sounds into a meaning

Question 5

Auditory stream segregation

Answer 5

A perceptual process by which the human auditory system groups sounds from different sources into perceptually meaningful elements
- Galloping sound
- Increased sound rate you start hearing two sounds

Question 6

Auditory scene analysis

Answer 6

Our ability to segregate and intergrate individual sounds relative to their sources
- Gestalt-like baic principles of grouping
When hearing sounds we tend to group acoustic components that
*similar across time
*are harmonically related

Question 7

Auditory Scene analysis - Problems

Answer 7

1. Which frequencies are present in the sound signal and come from the same source?
2. Sound stream
   A source producing discrete sounds over time (footsteps)
3. Very bottom-up process
   Context gives familiarity with certain sounds

Question 8

Bistable sound illusions

Answer 8

Analogue to reversibility figures in vision, hearing something in two different ways
- Galloping sound
Perception can change for the same melody
- Rapid sequence of repeated syllables or words

Question 9

How can locate sounds?

Answer 9

Often from binaural hearing
We use both of our ears, sounds rarely comes directly in front of us
Often listen to the pitch to figure out where the source is from
- Survival insticts

Question 10

Interaural time difference*

Answer 10

Sounds arrive first at ear closest to the sound
- Low Hz

Question 11

Interaural intensity difference*

Answer 11

Sounds are loudest at ear closest to the sound
- High Hz

Question 12

How do we recognize sounds?

Answer 12

• Often by pitch
  Subtle changes
• Different languages has different pitches

Question 13

How do we recognize speech sounds?

Answer 13

Phoneme categories
Dialetcts, certain phonemes overlap
- Categorical perception
- Invariance problem
- Context matters
State of the person changes perception as well

Question 14

What can some spectrograms illustrate?

Answer 14

That two phonemes can be categorized as the same despite physical differences

Question 15

Mismatch Negativity

Answer 15

• Violation of expectations in a sequence of sounds
  One sound deviates from the rest
  Brain loves expectations

Question 16

The interaural level difference

Answer 16

Difference in loudness and frequency distribution between the two ears