15th International Congress of Phonetic Sciences (ICPhS-15)
A common type of stop is voiceless and unaspirated, sometimes contrasting with a voiced one. In English this is true in certain contexts, but utterance-initially the two types vary freely, both heard as voiced by phonetically naive native speakers, though linguists sometimes describe the first as "devoiced" and/or the second as "prevoiced." Moreover, wherever a voiceless inaspirate context is edited so the stop release + opening transition come to be utterance-initial, the stop is perceived as voiced. In Russian stops are either voiced or voiceless unaspirated, the two being in contrast initially and medially. Unlike the case in English, whose voiceless inaspirates have context-determined phonological and perceptual status, the voiceless inaspirates of Russian are everywhere reported as voiceless, a perception shared by speakers of Russian, English, and French.
Bibliographic reference. Lisker, Leigh (2003): "On perceiving certain voiceless unaspirated stops", In ICPhS-15, 821-824.