Heard this call while birding during daytime and recorded a few seconds. ID threw me for a bit until I was able to get binoculars on perched Acadian Flycatcher. Single noted calls occuring between 11 and 21 second mark may be additional calls to search for at night beside "pseet seeup" call.
Acadian Flycatcher "pseet seeup" call recorded on 5-15-06, time unknown
I am not sure exactly what time this was recorded except to note that it was made between 11 PM and prior to the start of the "dawn chorus." No way to tell if this call was made in flight or from a perched location. Habitat around my house is not conducive for Acadian Flycatchers. I have had Eastern Wood-pewee pass through my yard during the day in Spring migration and a "traill's" type flycatcher pass through in the Fall. *2007 update - I recorded another Acadian Flycatcher "pseet-seeup" call on 5/5/07.
Closer view of same call above
Perched Acadian Flycatcher giving an alternative call during daytime on 5-17-10 (Little Bennett RP, Mont Co, MD)