The phonetics of postnasal voicing

Many of the world’s languages display a phonetic pattern whereby obstruents appear as voiced when following a nasal consonant. This article proposes a phonetic mechanism that favors postnasal voicing. The mechanism is based on two effects, which sometimes reinforce, and sometimes contradict each another. One effect is “nasal leak,” the leakage of air through a nearly closed velar port during the coarticulatory period between an oral and a nasal segment. The other is “velar pumping,” which arises from the vertical motion of a closed velum