I'd like to thank everyone concerned for your input on the mystery sounds!! So the consensus 
is it's a spring peeper, prompted perhaps by the shortening days; and possibly a young male 
trying out his voice. Our house is next to a wetland and in the spring the peepers are 
deafening. (http://onejackdaw.com/Audio/Spring_Peepers.mp3) And yes, Kent, I am going to 
enter my recordings into the Vermont Atlas of Life 
http://www.inaturalist.org/projects/vermont-atlas-of-life. 

Hilke Breder
Brattleboro