The Collaborative International Dictionary of English v.0.48:

Phonic \Phon"ic\ (f[o^]n"[i^]k; 277), a. [Gr. fwnh` sound: cf.
   F. phonique.]
   Of or pertaining to sound; of the nature of sound; acoustic.
   --Tyndall.
   [1913 Webster]

WordNet (r) 3.0 (2006):

phonic
    adj 1: pertaining to the phonic method of teaching reading
    2: relating to speech
    3: of or relating to speech sounds; "phonetic transcription"
       [syn: phonetic, phonic]

Moby Thesaurus II by Grady Ward, 1.0:

106 Moby Thesaurus words for "phonic":
   accented, acoustic, alveolar, apical, apico-alveolar, apico-dental,
   articulated, assimilated, audible, audile, audio, auditory, aural,
   auricular, back, barytone, bilabial, broad, cacuminal, central,
   cerebral, checked, close, consonant, consonantal, continuant,
   dental, dissimilated, dorsal, flat, front, glide, glossal, glottal,
   guttural, hard, hearing, heavy, high, hypersonic, intonated,
   labial, labiodental, labiovelar, lateral, lax, light, lingual,
   liquid, low, mid, monophthongal, muted, narrow, nasal, nasalized,
   occlusive, open, otic, otological, otopathic, otoscopic, oxytone,
   palatal, palatalized, pharyngeal, pharyngealized, phonemic,
   phonetic, pitch, pitched, posttonic, retroflex, rounded, semivowel,
   soft, sonant, sonic, stopped, stressed, strong, subsonic,
   supersonic, surd, syllabic, tense, thick, throaty, tonal, tonic,
   transonic, transsonic, twangy, ultrasonic, unaccented, unrounded,
   unstressed, velar, vocalic, vocoid, voiced, voiceless, vowel,
   vowellike, weak, wide