Cognates

According to dictionary.com, a "cognate" is related by birth; of the same parentage, descent, etc.

When we apply that to consonants in Diction for Singers, we are talking about consonants that are only differentiated by their voicing:

For example:
[p] and [b] have the same "middle name" and "last name" - they are only differentiated by their voicing so they are "cognates."

[p] is unvoiced - bilabial - plosive
[b] is voiced - bilabial - plosive

The two other pairs of cognates:

 [d] and [t]  (these are voiced/unvoiced - alveolar - plosives)

 [g] and [k]  (these are voiced/unvoiced - velar - plosives)