Divisive issue 2:
Complete explanation?

·   Target extraction (Brown/Cooke)

- `pluck-out' that which fits model
... and ignore the rest?

·   Complete explanation (Ellis)

- create objects to cover all features
- nothing ignored

·   Humans listen to everything

- evolution: unknown sound = danger?
- can compensate for interactions (restoration)
- must take account of unwanted sounds
- (restoration requires knowledge)