Modifiers matching channel:

• secure,
• tubular,
• elastic,
• main,
• linear,
• logical,
• wireless,
• common,
• extraneous,
• natural,
• round,
• closed,
• alternative,
• artificial,
• narrow,
• single,
• physical,
• same,
• over,
• shared,
• spectral,
• current,
• noisy,

Simple categories matching spectral:

• property,
• parameter,
• distortion,
• information,
• channel,
• shape,
• band,
• characteristic,
• change,
• measure,
• quantity,
• behavior,
• line,
• sonority,
• variation,
• artefact,
• region,
• component,
• structure,
• color,
• transformation,
• energy,
• attribute,
• range,
• feature,
• composition,
• analysis,