Constant BAND_EDGE_CONVENTION 

pub const BAND_EDGE_CONVENTION: &str = "long-term power spectrum of the mid over the active \
frames that lie wholly inside the stem, median-smoothed over one semitone on each side; where \
the smoothed level falls at least 25 dB over one semitone above 2 kHz and the median level of \
the octave below lies within 20 dB of the level where the fall starts, the edge is the \
half-depth point of the steepest such fall; otherwise the noise floor is the lowest level above \
1 kHz and the edge is the highest bin at least 30 dB above it, at low confidence, or the Nyquist \
frequency when no bin above 1 kHz is";

The convention of the band edge.