Frequency domain dithering adds white noise to the spectrum. The noise intensity is determined per quantization unit. The first two quantization units get no noise at all, the noise amplitude is determined by

• The quantization units' quantization precision
• The quantization units' level
• The band envelope
• The number of the band, indexing a per-frame noise level table
  • Noise level for band 0 is the first entry
  • Noise level for bands 1-2 is the second entry
  • Noise level for bands 3-5 is the third entry
  • Noise level for bands 6-10 is the fourth entry
  • Noise level for bands 11-15 is the fifth entry