Assertion: american crow's call | /r/HasProperty | simple
Facets:
value: in frequency structure
type: OTHER
value: relatively
type: DEGREE
value: usually
type: DEGREE
Source sentences:
text: Calls are usually relatively simple, resembling whistles, flutes, or hiccups.
text: The calls of abundant species or calls that are simple in frequency structure and show little amplitude modulation are preferentially imitated.