{"id": "card_acoustics_loudness", "kind": "reference", "title": "Loudness — the decibel, a logarithm", "body": "The ear spans a trillion-fold range, so loudness is measured in decibels: every 10 dB is a tenfold power ratio, 30 dB a thousandfold (sealed). Perception compresses huge ranges logarithmically. Rests on the mind.", "source": {"label": "Narrow Highway — acoustics", "url": "", "authority_tier": "engine_derived"}, "shelf": "codex", "box": "acoustics", "bands": ["acoustics", "pillar", "loudness", "one map"], "subject": "Loudness — the decibel, a logarithm", "connections": [{"to_card_id": "card_floor_acoustics", "relationship": "part_of", "evidence": "a pillar of acoustics (Loudness)"}, {"to_card_id": "card_floor_the_mind", "relationship": "connects_at", "evidence": "loudness is logarithmic perception - the decibel, a psychophysical scale"}], "author": "engine", "created_at": 0.0, "updated_at": 0.0, "visibility": "public", "lifecycle_stage": "public", "volatility": "permanent", "surface": "secular", "generated": false, "call": "codex.acoustics", "facets": {"subject": ["loudness", "one map", "pillar"]}, "presentation": {"glyph": "•", "kind_label": "acoustics", "by": "Narrow Highway — acoustics", "authority": "engine_derived", "posted": "", "standing": ""}, "neighbors": [{"id": "card_floor_acoustics", "title": "Acoustics — waves, loudness, and harmonics", "relationship": "part of", "why": "a pillar of acoustics (Loudness)", "href": "/card/card_floor_acoustics", "resolved": true}, {"id": "card_floor_the_mind", "title": "The mind — matter aware of itself", "relationship": "connects at", "why": "loudness is logarithmic perception - the decibel, a psychophysical scale", "href": "/card/card_floor_the_mind", "resolved": true}], "house": {"door": "FIND", "kind": "card", "trail": "connections", "seal": "/card/card_acoustics_loudness", "next_step": {"do": "follow a connection: what this card rests on, and what rests on it", "door": "FIND", "tool": "card_connections", "params": {"id": "card_acoustics_loudness"}}, "ends": "a verdict or a card · the trail · a seal · one next step"}}