':return: the given file(s) as a floating number
:rtype: list(float)'

def MLU(self, fileids=None, speaker='CHI'):

    if (not self._lazy):
        return [self._getMLU(fileid, speaker=speaker) for fileid in self.abspaths(fileids)]
    get_MLU = (lambda fileid: self._getMLU(fileid, speaker=speaker))
    return LazyMap(get_MLU, self.abspaths(fileids))
