I learnt that a word like 花 (はな) is of pitch pattern (2), i.e. with a drop after the last mora in case it is followed by a particle. Yet, when I hear people use a word like this is combination with the -を particle, it sounds to me like it is of pitch pattern (0), i.e. with no drop at all (accentless). Take, for instance, the sentence 花を買いました, where I cannot detect a drop.
My ear is not very trained in that sense, so I might be mistaken; but I have heard a lot of similar sentences in which I cannot detect a drop.
Can somebody confirm/refute my hunch? Even better, does anybody know the general rule (assuming there is one) in relation to the -を particle, and perhaps even related to other very common particles, such as -が, -は and -に?
Many thanks in advance!