Is the 19-week scan the anomoly scan? I'm not sure how normal it is but our hospital sends out a leaflet about the20-week anomoly scan which states that for the most accurate results the scan should be done in a darkened room and in relative silence (not "no talking" but keeping it all to a minimum) because the sonographer has to really concentrate to look for some of the things the scan is supposed to be spotting. We're skipping our anomoly scan anyway so i guess i'll not find out how true it is. BUt in any case you should complain, because if they couldn't answer your questions due to having to concentrate they should have at least told you that, rather than just ignoring you.

Bx