The main aim of the present study was to investigate the extent to which East Franconian speakers neutralize the voicing opposition in intervocalic stops when they produce a variety of Standard German. A second aim was to test whether young and old speakers differ in their extent of neutralization and tend to a more standard-like pronunciation. We analyzed contrast maintenance by means of the vowel-to-stop duration ratio. An acoustic analysis of leiden-leiten revealed that old East Franconian speakers neutralized the voicing contrast either completely or to a greater extent than young East Franconian speakers. Young East Franconian speakers preserved the voicing contrast, although to a lesser extent than the Standard German speakers. A forced choice perception experiment showed that young but not old East Franconians perceived the lenis/fortis contrast. The results point to a sound change in progress in which a phonemic [± voice] stop distinction is developing in East Franconian.