How do Eastern Armenian and Western Armenian differ in pronunciation?

The primary difference in pronunciation between Eastern and Western Armenian stems from a significant shift in the plosive consonant system inherited from Old Armenian.1

In Eastern Armenian, the pronunciation of consonants generally retains a closer correspondence to the Old Armenian system. Specifically, it utilizes voiced consonants, intensive voiceless slightly glottalized plosives, and voiceless slightly aspirated plosives.1

In contrast, Western Armenian underwent a distinct consonant shift:
* Old Armenian voiced consonants (b, d, g, j, dz) are pronounced as voiceless (and sometimes voiceless aspirated) in Western Armenian, effectively merging with the Old Armenian voiceless aspirated series.1
* Old Armenian voiceless plosives (p, t, k, c, ch) are pronounced as voiced (/b, d, g, j, dz/) in Western Armenian.1

This divergence is clearly illustrated by the pronunciation of names of Greek origin. For example, the name "Petros" is pronounced as /Petros/ in Eastern Armenian, but as /Bedros/ in Western Armenian; similarly, "Grigor" becomes /Krikor/ in the Western variety. These phonetic differences are so significant that the two varieties are sometimes considered distinct languages.12