The Collaborative International Dictionary of English v.0.48:

Screechy \Screech"y\, a.
   Like a screech; shrill and harsh.
   [1913 Webster]

WordNet (r) 3.0 (2006):

screechy
    adj 1: having or making a high-pitched sound such as that made
           by a mouse or a rusty hinge [syn: screaky, screechy,
           squeaking, squeaky, squealing]