##' @param silsuffix the suffix of the silence profile files 'c.mp3.csv'. The format of such files should be the format used by Audacity label files, i.e. 'start time, end time, label' (without header), where 'label' should be 'silence'
##' @param srdir directory where speech rate csv (1 value per utterance) files are stored
##' @param srsuffix the suffix of the speech rate files (default: sre)
##' @Param sprate compute speech rate? (default: TRUE; this has no effect at the moment)
##' @param sprate compute speech rate? (default: TRUE; this has no effect at the moment)
##' @param sprate compute speech rate? (not in use yet)
##' @return a session's vocalisation feature stats