It sounds like you're asking for an interesting guide related to in the context of Engine Engineering or Mechanical Tolerances — specifically, something like "ISO 303" or a "Sone" scale for perceived loudness? Let me clarify and provide a useful guide.
If you meant as a technical course/module code (e.g., in an engineering curriculum), it might refer to Acoustics & Noise Control (since "Sone" is a unit of loudness). sone 303 eng