Well ..... yes and no ...
PAL is 25 fps (frames
per second)
NTSC is 23.976(24) or 29.97fps -- again, frames
per second
60
seconds of audio will be the same either way. The video framerate has no affect on the audio.
The exemption here, however, is when 23.976 progressive NTSC video is sped up to 25fps -- one extra frame is played each second -- thereby increasing the audio speed by about 4% to match.
This is explained a bit more on the
PAL to NTSC conversion guide on the site, including information on the proper ways to convert both audio and video.