Assertion: tone's pitch | /r/CapableOf | decrease with time
Facets:
value: in a process
type: TEMPORAL
Source sentences:
text: As a result, when one combines tone with sentence prosody, the absolute pitch of a high tone at the end of a prosodic unit may be lower than that of a low tone at the beginning of the unit, because of the universal tendency (in both tonal and non-tonal languages) for pitch to decrease with time in a process called downdrift.