getting punch in vocal to match old track

[village1]

Is there any technology to help do this? Or is just be ear?

Thanks,

Giovanni

[KingTor]

record the replacement in the same room with the same mic, pre-amp, placement; have the singer listen to and mimic the previous performance as closely as possible, &c, &c.

if it doesn't match, EQ by ear is the only technology I'm aware of. An analyser like the Waves PAZ plug, or Spectra Foo will help you analize which frequencies might need help.