Options and their meanings are:
-I Identify program and exit.
-i item Select input item.
-c mulaw Perform amplitude compression on the signal. This reduces the dynamic range of the signal, making quieter components more salient. A mu-law compression function is used: Select compression-style enhancement using a mu-law compression function: output_energy = log(1+mu.input_energy)/log(1+mu). A mu value of 10 gives modest compression.
-s spectsubdegree Perform spectral subtraction on the signal. This reduces the amount of background noise in the signal by subtracting a fraction of the quietest frames from all frames (in the frequency domain). The degree is a percentage factor on the energy found in the quietest frames. A degree of 100 gives modest background noise removal.
-f fixdB Select fixed amplitude scaling by the specified number of decibels.
-A label Only process the regions annotated with this label. You can specify multiple regions.
-X label Process all regions except those annotated with this label. You can specify multiple regions.
1.xx Any speech item.
1.0 - Mark Huckvale. 1.1 - John Rye. 2.0 - Mark Huckvale.