Is it possible to have audio record also at the slow-motion modes 400 fps and 1200 fps (nikon 1 j1/v1) ? At this Youtube:

you can see a application which tried to measure the really time between video and audio.

I do not know really what you need to know. I'll describe it from the view of a audio engineer. The problem for all (smaller) post pro audio studios is to manage the right timing - as you can see at much videos the synchrony of pictures and audio are not really a solved issue. The problem is most audio workstations have literally no delay for replay audio, less then 10millisecounds is absolute normal.
If you produce CD or MP3 this is fine more and more small studios have to go multimedia - so video came in their business.

There customers now bring in some video and the good old audio studio now will make audio post. No problem for the first. The digital work station can handle video already and they have monitors. This monitors work very well but all but also the most expensive will have delays. The first delay is in depence of the codec you are using. The PC needs some time to decode the mp4 or the mpeg1 and needs different time for each format. After this the monitor needs some time to get the RGB and put it to the LCD. This video frame will be optimized at the monitor. This monitor get first the whole frame, after this it makes some sharpness and overscan this also costs time. At the end you'll have, in depence of your video, which is only played from your audio workstation (no further processing), delays up to 4 frames between reading on your hard disc and the time the picture is viewable at your screen or beamer. But is is not really exact whole frames. The result may is, the protagonist at the film has a perfect end on the street, but in the movie the body hits the ground 100 milliseconds after the really big boom and this, you can really see. ok.

So the vendors of good audio workstations know this and have timing preferences to be set. If you in a big studio you will find some experienced cutter which can really see picture sound differences up to 1/4th of a frame but a audio pro has at this point not really a chance. And the challenge is to find the right time delay for your equipment with the specific codec at your MAC/PC.

So big tolerances as described above are easy to compensate roughly but for professional look this way is mostly crap.

The next problem for smaller studios is the work prozess are not standardised, always timing troubles happen before you start, because the video editor makes on the top also often mistakes. Really this daily happens !

Now I think may the nikon came in. If you can record the picture of your LCD and time syncron also record the audio beeps or claps. Then you can really make sure the delay at the recorded movie. So you can make a really good quality check at all movies which are at your place. If you become source material of the filmset you'll always have claps to synchronize since the beginning of the movie sound - why when this is not a really problem ...

The movie at youtube shows a way you can roughly measure the visual clap/point/count what ever to a timesynchon recorded audio. It makes two separate signals (picture and sound - sound quality not matters) which you can move for and back against each other and the time you moving around is the time you have to put in the preferences of the workstation. But only the news phone will have a precision of 1/4th of a frame this will do it i think but with 1200 frames per second this can really be more precise.

After setting the right delay you have at your production no hassle with timing anymore.

Yep and the nikon has a microphone and has 1200 pictures per second so theoretically you have the hardware and you can measure with it picture and sound delays. (i know this will not a function which will be placed inside the cam, the cam has enough processing power to do this, but this is not a function of a cam) If you have a movie (5 seconds really enough) and you can count the pictures between sound and impact you have a really big source !

I hope this is really understandable - my english is not very well I know.