Americans who learned English as children and were either born overseas or grew up in a family in which foreign languages––particularly, German––were spoken by the parents or other close relatives may pick up and unknowingly import one or another heterolingual phonetic trait into their own speech. This is the case with the so-called incomplete voicing of initial stop consonants such as [b] in boy or [dʒ] in judge, which one occasionally hears on the radio from announcers whose family background probably includes non-native speakers of American English.
The incompleteness pertains to the onset of the stop, which is to say that the speaker starts by pronouncing the consonant without voicing––i. e., delays the vibration of the vocal bands––and only midway through its articulation actuates the vocal bands.
Two radio personalities who regularly manifest this trait are Terry Gross of the program Fresh Air (on NPR) and Jim Svejda (on-air host on KUSC, the classical music station of the University of Southern California). Gross apparently grew up in Brooklyn and must have encountered many speakers of Yiddish as a child. The origin of this feature in Svejda’s speech is unclear, but given the fact that this surname derives from Bohemia and the Austro-Hungarian area in general, one suspects a German-speaking milieu somewhere in America as the likely source.
[ADDENDUM: In answer to my query about his background, Mr. Svejda kindly responded as follows: “It was 22nd Street Chicago English (with a Czech accent) leavened by Arkansas white trash; I also spent several years in speech therapy for various afflictions, including a lateral lisp.”]