Windowing operation on spectrograms

[m-ali-awan]

I am working on cough detection, and using COUGHVID dataset, where most of the audio files are of 9-sec length, but the range is from 1 sec to 9 sec
Also the cough score is from 0.0 to 1.0, and no particular threshold can be used, as there are cases where there is no cough in a sample with a score of around 0.3, but the mild cough is there with score 0.2.

Now I want to keep my spectrogram window around 2-3 sec, how to use windowing in fastaudio?
As once I will be using 2-3 sec clips then it is going to pollute labels, as may be in only one clip cough would be there, so kindly suggest to me what you think of it.
And last but not the least, how to use label-smoothing in fastaudio?
Thanks...