Can I store the spectrogram matrix into a cell for each wav file, read by audioDatastore?

X=[];
numFiles=3000;
for i = 1:numFiles
    [x,~] = read(ads);
    fs = 16000;
    frameLength = round(frameDuration*fs);
    hopLength = round(hopDuration*fs);
    
    spec = melSpectrogram(x,fs, ...
        'WindowLength',frameLength, ...
        'OverlapLength',frameLength - hopLength, ...
        'FFTLength',640, ...
        'NumBands',numBands, ...
        'FrequencyRange',[50,8000]);
    X{i,:}={spec} 
    spec=[]
    
end

Actually I want to store all these spectrogram values for each wav files into cells (such that a cell X has 1X3000 dimention has 3000 cells of dimention 50X140 say )to follow this example and eventually each label into a matrix of 5X3000 ,such that each coloumn has single 1 and rest 0's.