Source : Webster's Revised Unabridged Dictionary (1913)

Perceptible \Per*cep"ti*ble\, a. [L. perceptibilis: cf. F.
   perceptible. See {Perceive}.]
   Capable of being perceived; cognizable; discernible;
   perceivable.

         With a perceptible blast of the air.     --Bacon.
   -- {Per*cep"ti*ble*ness}, n. -- {Per*cep"ti*bly}, adv.

Source : WordNet®

perceptibly
     adv : in a noticeable manner; "he changed noticeably over the
           years" [syn: {noticeably}] [ant: {imperceptibly}]