(suffix)(speech)loquy

alieniloquy     speech on subjects other than the matter at hand; off-topic speech
alloquy         speaking to another or many others; an address  .
amphoriloquy    cavernous voice of a patient heard over a patient's lung cavity
anteloquy       a preface
antiloquy       speaking against some idea; contradicting or gainsaying
caverniloquy    cavernous voice of a patient heard over a patient's lung cavity
centiloquy      work consisting of one hundred aphorisms, attributed to Ptolemy
colloquy        speaking together; mutual discourse .
obloquy         censure; calumny; slander; disgrace.
parciloquy      laconic speech.
pectoriloquy    sound of patient’s voice as heard through stethoscope.
soliloquy       talking or conversing with oneself; dramatic production of
this nature.
tristiloquy     mournful manner of speech.
ambiloquous     using dubious or ambiguous expressions.
ventriloquism   speaking so that the voice appears to come from elsewhere.
biloquist       one capable of speaking with two distinct voices.
gastriloquist   ventriloquist.