The best and natural way is to sing in sync and use of EQ to reduce sss and other bad artefacts..
If you have no other choices, there is one tool that seem promessing : http://www.synchroarts.com/products/vocalign-pro/overview

Cameron21, post: 428377, member: 49031 wrote: Like the word "Boat" is pretty easy to line up, but "Stack" isn't so much. Do you line it up with the start of the 'sss' sound, or the 'tttt' or the vowel?

I dunno... IMO, I think you might be being a bit too picky about this... how many "S's or 'T's" are you adding to the word? I mean, unless you're really dragging out syllabic consonants, I really don't know anyone who sweats that much over whether or not the "S" in Stack or the "T" in Stack lines up precisely with the downbeat, unless you are really stretching those "S's" out beforehand. I suppose it depends on tempo and style, and, when you are comping, how late - or early - are the comped vox in respect to the beat? Are we talking being off off by 1/16ths, 1/8's, full 1/4 note beats? Or off by something much smaller, like ticks or frames?

You could engage a metronome during playback and do it by ear, or, you can find the start of the beat/measure visually by looking at either the measure/beat markers on your timeline editor, or, you can also use one of your existing transient tracks (like kick drum, hi hat,etc) as a visual cue and line them up that way as well.

There are also some DAW's which have an audio quantize feature, which allows the user to define a certain resolution, at which point, just like midi, the vocals are automatically lined up to a beat, but, you can also get some pretty weird artifacts doing it that way, because in order for it to work, sometimes words, syllables, consonants, etc., can be sped up, slowed down, or, even chopped off. The quantize command is looking for the easiest way to shift all those parts so that they reflect a particular note or tick/frame resolution that is set by you.

Depending on the style, it can be important to have good timing and have a word/phrase start at the same time as the down, but doing that all the time can also make things pretty stiff and robotic too.

I'd be more concerned with making sure that the phrasing as a whole sits well within an entire section, and/or, if you have multiple vocals happening that all sing the same parts - like doubled lead vocals or backing vocals - that they all end at the same time, particularly with words that end in S, T, CH and K (or hard C) and Z (or "zed" for our Canadian members LOL).

Often, relaxed vocals, with phrasing that isn't precisely in line to the beat, can add more feeling and vibe to a track, as opposed to everything always lining up exactly with a beat all the time...

IMHO of course.

If the waveforms look so different that lining them up is tricky, they tend not to work as replacements anyway. I always experiment with stretching the waveform vertically, as it can show the edges better, which always seems to work for me.

Yeah I agree with Donny here . I know because Ive waisted hours lining stuff up and it comes out sounding boring ....lol
Just let it be what it is or do it again , the time you spend stuffing around is better off spent on practising the real thing :cool:

This is where elastic audio gets its cool. ProTools. recorded to a click which becomes the grid. In elastic you see the wave form and you are able to stretch or collapse and compensate within a reasonable amount of the beat bar without loss of fidelity or realism. And you can retain the feel of the vocal sliding into a word or stretching a syllable to fill a 'feel gap' without pitchy tuned sounding results.

Dinitial performer does this as well, very useful.

Like everyone else, I'd recommend doing enough takes to where one of them lines up. But you also tend to get attached to certain takes or just don't have enough time to keep the vocalist in the studio. I've heard of the Vocalign plugins years ago but never got to try them.

I'd just cut and move them as you need to, and cross fade (sinusoidal, linear, whatever works best) so you don't get the weird blips at the cuts. That's how I used to do it, and it worked flawlessly, albeit took a lot of time. I always treat my vocals manually though. It's going to get the most attention.