Recognition chime timing (D-067), 5-bus audio architecture (D-068), audio dip profiles (D-069), confrontation as cognitive vulnerability (D-070), monologue chime placeholder strategy (D-071), universal conversation murmur (D-072), zone crossfade (D-073), hybrid audio generation (D-074). Amends D-038 scope, resolves Q-014. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>