diff --git a/client/tests/test_audio_bus_routing.gd b/client/tests/test_audio_bus_routing.gd
index f0df0eb2b..8dda3e962 100644
--- a/client/tests/test_audio_bus_routing.gd
+++ b/client/tests/test_audio_bus_routing.gd
@@ -15,10 +15,16 @@ extends GdUnitTestSuite
 
 func before_test() -> void:
 	AudioManager.clear_dip()
+	for bus in AudioManager.BUSES:
+		AudioManager.set_volume(bus, 0.0)
+	GameState.stationary_ticks = 0
+	GameState._prev_player_position = Vector2(-1e9, -1e9)
 
 
 func after_test() -> void:
 	AudioManager.clear_dip()
+	GameState.stationary_ticks = 0
+	GameState._prev_player_position = Vector2(-1e9, -1e9)
 
 
 # ==============================================================================
@@ -171,22 +177,25 @@ func test_audio_manager_apply_unknown_dip_leaves_state_unchanged() -> void:
 
 func test_audio_manager_apply_dip_emits_dip_changed_signal() -> void:
 	## apply_dip() must emit dip_changed(profile) synchronously.
-	var received_profile := ""
-	var conn := func(p: String) -> void: received_profile = p
+	## Array wrapper used for lambda capture — GDScript 4 captures String locals by value,
+	## so a mutable reference type is required to observe signal argument inside the closure.
+	var received := [""]
+	var conn := func(p: String) -> void: received[0] = p
 	AudioManager.dip_changed.connect(conn)
 	AudioManager.apply_dip("dialogue")
 	AudioManager.dip_changed.disconnect(conn)
-	assert_that(received_profile).is_equal("dialogue")
+	assert_that(received[0]).is_equal("dialogue")
 
 func test_audio_manager_clear_dip_emits_dip_changed_empty() -> void:
 	## clear_dip() must emit dip_changed("") to signal audio restored.
+	## Array wrapper used for lambda capture — same reason as apply_dip signal test above.
 	AudioManager.apply_dip("dialogue")
-	var received_profile := "sentinel"
-	var conn := func(p: String) -> void: received_profile = p
+	var received := ["sentinel"]
+	var conn := func(p: String) -> void: received[0] = p
 	AudioManager.dip_changed.connect(conn)
 	AudioManager.clear_dip()
 	AudioManager.dip_changed.disconnect(conn)
-	assert_that(received_profile).is_equal("")
+	assert_that(received[0]).is_equal("")
 
 func test_audio_manager_apply_dip_interrupts_previous() -> void:
 	## Switching profiles mid-dip: active profile must update to the new one.
@@ -196,13 +205,14 @@ func test_audio_manager_apply_dip_interrupts_previous() -> void:
 
 func test_audio_manager_dip_changed_fires_on_profile_switch() -> void:
 	## Switching from dialogue to confrontation emits dip_changed("confrontation").
+	## Array wrapper used for lambda capture — same reason as apply_dip signal test above.
 	AudioManager.apply_dip("dialogue")
-	var received_profile := ""
-	var conn := func(p: String) -> void: received_profile = p
+	var received := [""]
+	var conn := func(p: String) -> void: received[0] = p
 	AudioManager.dip_changed.connect(conn)
 	AudioManager.apply_dip("confrontation")
 	AudioManager.dip_changed.disconnect(conn)
-	assert_that(received_profile).is_equal("confrontation")
+	assert_that(received[0]).is_equal("confrontation")
 
 func test_audio_manager_has_asset_false_for_unknown_key() -> void:
 	## has_asset() must return false for a key that was never registered.
@@ -291,3 +301,57 @@ func test_audio_manager_play_sound_event_noop_for_empty_type() -> void:
 	## #125: Empty event type string must be a no-op.
 	AudioManager.play_sound_event("", Vector2(5.0, 5.0))
 	# No assertion needed — absence of crash is the test.
+
+
+# ==============================================================================
+# Layer 6: D-071 (#530) — Stationary tick tracking for ListeningFocus
+# ==============================================================================
+
+func test_d071_stationary_ticks_increments_when_position_unchanged() -> void:
+	## D-071: stationary_ticks must increment on each snapshot where player doesn't move.
+	var player_entity := {"entity_id": 1, "x": 10.0, "y": 10.0, "z": 0, "kind": {"variant": "Player", "data": {}}}
+	GameState.apply_snapshot({"tick": 1, "entities": [player_entity]})
+	GameState.apply_snapshot({"tick": 2, "entities": [player_entity]})
+	GameState.apply_snapshot({"tick": 3, "entities": [player_entity]})
+	assert_that(GameState.stationary_ticks).is_equal(2)  # 2 ticks of no movement (tick 2 and 3)
+
+func test_d071_stationary_ticks_resets_on_movement() -> void:
+	## D-071: stationary_ticks must reset to 0 when the player position changes.
+	var pos_a := {"entity_id": 1, "x": 10.0, "y": 10.0, "z": 0, "kind": {"variant": "Player", "data": {}}}
+	var pos_b := {"entity_id": 1, "x": 11.0, "y": 10.0, "z": 0, "kind": {"variant": "Player", "data": {}}}
+	GameState.apply_snapshot({"tick": 1, "entities": [pos_a]})
+	GameState.apply_snapshot({"tick": 2, "entities": [pos_a]})
+	assert_that(GameState.stationary_ticks).is_equal(1)
+	GameState.apply_snapshot({"tick": 3, "entities": [pos_b]})
+	assert_that(GameState.stationary_ticks).is_equal(0)
+
+func test_d071_stationary_ticks_reaches_threshold() -> void:
+	## D-071: stationary_ticks must be able to reach 30+ for ListeningFocus activation.
+	var player_entity := {"entity_id": 1, "x": 5.0, "y": 5.0, "z": 0, "kind": {"variant": "Player", "data": {}}}
+	for tick in range(31):
+		GameState.apply_snapshot({"tick": tick, "entities": [player_entity]})
+	assert_that(GameState.stationary_ticks >= 30).is_true()
+
+
+# ==============================================================================
+# Layer 7: D-069 (#530) — Dialogue dip profile interaction
+# ==============================================================================
+
+func test_d069_dialogue_dip_overridden_by_confrontation() -> void:
+	## D-069: Confrontation dip must override dialogue dip (apply_dip interrupts).
+	AudioManager.apply_dip("dialogue")
+	assert_that(AudioManager.get_active_dip()).is_equal("dialogue")
+	AudioManager.apply_dip("confrontation")
+	assert_that(AudioManager.get_active_dip()).is_equal("confrontation")
+
+func test_d069_listening_focus_cleared_by_dialogue() -> void:
+	## D-069: Dialogue dip must override listening_focus (higher priority focus state).
+	AudioManager.apply_dip("listening_focus")
+	assert_that(AudioManager.get_active_dip()).is_equal("listening_focus")
+	AudioManager.apply_dip("dialogue")
+	assert_that(AudioManager.get_active_dip()).is_equal("dialogue")
+
+func test_d069_clear_dip_noop_when_empty() -> void:
+	## D-069: clear_dip() when no dip active must be a safe no-op.
+	AudioManager.clear_dip()  # Should not crash
+	assert_that(AudioManager.get_active_dip()).is_equal("")
diff --git a/client/tests/test_audio_sprint13.gd b/client/tests/test_audio_sprint13.gd
new file mode 100644
index 000000000..f8a3cc79d
--- /dev/null
+++ b/client/tests/test_audio_sprint13.gd
@@ -0,0 +1,560 @@
+## Test suite for Sprint 13 audio tickets (D-067, D-068, D-069, D-071, D-072, D-073).
+##
+## Spec refs:
+##   D-067: Recognition chime fires at ONSET of cognitive delay, not at completion.
+##   D-068: 5-bus audio architecture (Music, Ambient, WorldSFX, PlayerActions, UISounds).
+##   D-069: Audio dip profiles — timing values, dB offsets, interruptibility.
+##   D-071: ListeningFocus boost (30+ tick gate, caller's responsibility).
+##   D-072: Universal NPC conversation murmur on WorldSFX — no zone-specific variants.
+##   D-073: Zone crossfade — hard boundary trigger, 1.5-2s tween, interruptible.
+##
+## Tickets covered:
+##   #529 — Zone crossfade implementation (set_zone body + tween timing)
+##   #530 — Dip profile call sites (dialogue/confrontation/ListeningFocus wiring)
+##   #531 — Recognition chime fires at cognitive delay onset
+##   #533 — NPC conversation murmur wired to WorldSFX bus
+##
+## Test layers:
+##   1. Zone crossfade spec and API (D-073 / #529)
+##   2. D-069 dip timing and dB spec values (supplementing test_audio_bus_routing)
+##   3. Volume slider proportional dip (D-068 / D-069)
+##   4. Dip call site wiring via GameState snapshot (D-069 / D-070 / #530)
+##   5. Recognition chime onset verification (D-067 / #531)
+##   6. NPC murmur routing (D-072 / #533)
+##   7. AudioManager no-op fallback sanity (D-068 / D-038)
+class_name TestAudioSprint13
+extends GdUnitTestSuite
+
+
+func before_test() -> void:
+	AudioManager.clear_dip()
+	AudioManager.stop_all_loops()
+	AudioManager.set_volume(AudioManager.BUS_AMBIENT, 0.0)
+	AudioManager.set_volume(AudioManager.BUS_WORLD_SFX, 0.0)
+	AudioManager.set_volume(AudioManager.BUS_UI_SOUNDS, 0.0)
+	AudioManager.set_volume(AudioManager.BUS_PLAYER_ACTIONS, 0.0)
+	AudioManager.set_volume(AudioManager.BUS_MUSIC, 0.0)
+
+
+func after_test() -> void:
+	AudioManager.clear_dip()
+	AudioManager.stop_all_loops()
+
+
+# ==============================================================================
+# Layer 1: Zone Crossfade — D-073 / #529
+# set_zone() stub exists now; full implementation lands in #529.
+# ==============================================================================
+
+func test_d073_set_zone_method_exists() -> void:
+	## D-073 / #529: AudioManager must expose set_zone(zone_id: String).
+	assert_that(AudioManager.has_method("set_zone")).is_true()
+
+
+func test_d073_set_zone_hub_does_not_crash() -> void:
+	## D-073: set_zone("hub") is a safe call. No crash even before #529 implementation.
+	AudioManager.set_zone("hub")
+
+
+func test_d073_set_zone_bar_does_not_crash() -> void:
+	## D-073: set_zone("bar") is a safe call.
+	AudioManager.set_zone("bar")
+
+
+func test_d073_set_zone_corridor_does_not_crash() -> void:
+	## D-073: set_zone("corridor") is a safe call.
+	AudioManager.set_zone("corridor")
+
+
+func test_d073_set_zone_empty_string_does_not_crash() -> void:
+	## D-073: set_zone("") edge case — no zone ID. Must not crash.
+	AudioManager.set_zone("")
+
+
+func test_d073_set_zone_unknown_zone_does_not_crash() -> void:
+	## D-073: Unmapped zone ID (no matching asset) — no crash, graceful no-op.
+	AudioManager.set_zone("nonexistent_zone_xyz")
+
+
+func test_d073_zone_asset_hub_key_matches_filename_convention() -> void:
+	## D-073 / #529: v0.1 zone-to-asset mapping per sprint brief.
+	## hub/workplace → amb_hub_layer (must match filename stem in res://audio/).
+	## Test verifies naming convention is documentable. Activates once #529 adds the map.
+	if not "ZONE_ASSETS" in AudioManager:
+		push_warning("TestAudioSprint13: ZONE_ASSETS not yet defined (#529 pending) — skip zone map test")
+		return
+	var zone_assets: Dictionary = AudioManager.ZONE_ASSETS
+	assert_that(zone_assets.has("hub")).is_true()
+	assert_that(zone_assets["hub"]).is_equal("amb_hub_layer")
+
+
+func test_d073_zone_asset_bar_key_matches_filename_convention() -> void:
+	## D-073 / #529: bar → amb_bar_layer
+	if not "ZONE_ASSETS" in AudioManager:
+		push_warning("TestAudioSprint13: ZONE_ASSETS not yet defined (#529 pending) — skip zone map test")
+		return
+	var zone_assets: Dictionary = AudioManager.ZONE_ASSETS
+	assert_that(zone_assets.has("bar")).is_true()
+	assert_that(zone_assets["bar"]).is_equal("amb_bar_layer")
+
+
+func test_d073_zone_asset_corridor_key_matches_filename_convention() -> void:
+	## D-073 / #529: smuggling corridor → amb_corridor_layer
+	if not "ZONE_ASSETS" in AudioManager:
+		push_warning("TestAudioSprint13: ZONE_ASSETS not yet defined (#529 pending) — skip zone map test")
+		return
+	var zone_assets: Dictionary = AudioManager.ZONE_ASSETS
+	assert_that(zone_assets.has("corridor")).is_true()
+	assert_that(zone_assets["corridor"]).is_equal("amb_corridor_layer")
+
+
+func test_d073_crossfade_duration_in_1_5_to_2_0s_range() -> void:
+	## D-073: Crossfade tween duration must be 1.5-2.0s.
+	## Activates once #529 defines the duration constant.
+	if not "CROSSFADE_DURATION" in AudioManager:
+		push_warning("TestAudioSprint13: CROSSFADE_DURATION not yet defined (#529 pending) — skip duration test")
+		return
+	var duration: float = AudioManager.CROSSFADE_DURATION
+	assert_that(duration >= 1.5 and duration <= 2.0).is_true()
+
+
+func test_d073_set_zone_same_zone_repeated_is_noop() -> void:
+	## D-073: Crossing back to the current zone should not restart a crossfade.
+	## (No audio pops when zone boundary is ambiguous.) Activates post-#529.
+	if not "ZONE_ASSETS" in AudioManager:
+		push_warning("TestAudioSprint13: set_zone body not yet implemented (#529) — skip no-op test")
+		return
+	AudioManager.set_zone("hub")
+	AudioManager.set_zone("hub")
+	## Expect exactly one or zero ambient players after same-zone calls (no stacked tweens).
+	## Stub: assert no crash and ambient_players size is 0 or 1, not 2.
+	assert_that(AudioManager._ambient_players.size() <= 1).is_true()
+
+
+# ==============================================================================
+# Layer 2: D-069 Dip Timing and dB Spec Values
+# These tests supplement test_audio_bus_routing.gd with timing and dB precision.
+# ==============================================================================
+
+func test_d069_dialogue_ease_in_is_300ms() -> void:
+	## D-069: Dialogue dip ease-in = 300ms (0.3s).
+	var ease_in: float = AudioManager.DIP_SPECS["dialogue"]["ease_in"]
+	assert_that(ease_in).is_equal_approx(0.3, 0.05)
+
+
+func test_d069_dialogue_ease_out_is_500ms() -> void:
+	## D-069: Dialogue dip ease-out = 500ms (0.5s).
+	var ease_out: float = AudioManager.DIP_SPECS["dialogue"]["ease_out"]
+	assert_that(ease_out).is_equal_approx(0.5, 0.05)
+
+
+func test_d069_confrontation_ease_in_is_500ms() -> void:
+	## D-069: Confrontation dip ease-in = 500ms (0.5s).
+	var ease_in: float = AudioManager.DIP_SPECS["confrontation"]["ease_in"]
+	assert_that(ease_in).is_equal_approx(0.5, 0.05)
+
+
+func test_d069_confrontation_ease_out_is_1000ms() -> void:
+	## D-069: Confrontation dip ease-out = 1000ms (1.0s) — longer exit for immersion.
+	var ease_out: float = AudioManager.DIP_SPECS["confrontation"]["ease_out"]
+	assert_that(ease_out).is_equal_approx(1.0, 0.05)
+
+
+func test_d069_dialogue_ambient_dip_within_6_to_8_db() -> void:
+	## D-069: Dialogue dip: Ambient -6 to -8dB. Mid-range value (-7) used.
+	var dip: float = AudioManager.DIP_SPECS["dialogue"]["buses"]["Ambient"]
+	assert_that(dip >= -8.0 and dip <= -6.0).is_true()
+
+
+func test_d069_confrontation_ambient_dip_within_10_to_12_db() -> void:
+	## D-069: Confrontation dip: Ambient -10 to -12dB. Mid-range value (-11) used.
+	var dip: float = AudioManager.DIP_SPECS["confrontation"]["buses"]["Ambient"]
+	assert_that(dip >= -12.0 and dip <= -10.0).is_true()
+
+
+func test_d069_confrontation_world_sfx_dip_within_4_to_6_db() -> void:
+	## D-069: Confrontation dip: WorldSFX -4 to -6dB (graduated — loud events break through).
+	var dip: float = AudioManager.DIP_SPECS["confrontation"]["buses"]["WorldSFX"]
+	assert_that(dip >= -6.0 and dip <= -4.0).is_true()
+
+
+func test_d069_listening_focus_world_sfx_boost_within_2_to_3_db() -> void:
+	## D-069 / D-071: ListeningFocus boosts WorldSFX +2 to +3dB (eavesdrop bonus).
+	var boost: float = AudioManager.DIP_SPECS["listening_focus"]["buses"]["WorldSFX"]
+	assert_that(boost >= 2.0 and boost <= 3.0).is_true()
+
+
+func test_d069_dialogue_spec_only_affects_ambient_bus() -> void:
+	## D-069: Dialogue dip touches ONLY Ambient. WorldSFX, PlayerActions, UISounds, Music
+	## must NOT appear in the spec — world events remain audible during conversation.
+	var buses: Dictionary = AudioManager.DIP_SPECS["dialogue"]["buses"]
+	assert_that(buses.has("Ambient")).is_true()
+	assert_that(buses.has("WorldSFX")).is_false()
+	assert_that(buses.has("PlayerActions")).is_false()
+	assert_that(buses.has("UISounds")).is_false()
+	assert_that(buses.has("Music")).is_false()
+
+
+func test_d069_confrontation_spec_does_not_affect_player_actions() -> void:
+	## D-069: Confrontation dip leaves PlayerActions at 0 — player sounds are NOT muffled.
+	var buses: Dictionary = AudioManager.DIP_SPECS["confrontation"]["buses"]
+	assert_that(buses.has("PlayerActions")).is_false()
+
+
+func test_d069_confrontation_spec_does_not_affect_ui_sounds() -> void:
+	## D-069: Confrontation dip leaves UISounds at 0 — chimes and UI remain audible.
+	var buses: Dictionary = AudioManager.DIP_SPECS["confrontation"]["buses"]
+	assert_that(buses.has("UISounds")).is_false()
+
+
+func test_d069_listening_focus_spec_does_not_affect_ambient() -> void:
+	## D-071: ListeningFocus boost is ONLY on WorldSFX. Ambient is NOT modified.
+	## D-071: Eavesdropping requires MORE ambient awareness, not less — no ambient dip.
+	var buses: Dictionary = AudioManager.DIP_SPECS["listening_focus"]["buses"]
+	assert_that(buses.has("Ambient")).is_false()
+
+
+func test_d069_filter_cutoff_default_is_approx_20khz() -> void:
+	## D-069: Default low-pass filter cutoff is ~20kHz — effectively bypassed.
+	## Confrontation dip sweeps it down to 800Hz. Default must be >= 20000Hz.
+	assert_that(AudioManager.FILTER_CUTOFF_DEFAULT >= 20000.0).is_true()
+
+
+func test_d069_confrontation_filter_hz_is_800hz() -> void:
+	## D-069: Confrontation sweeps low-pass filter to ~800Hz for muffled feel (D-070).
+	var filter_hz: float = AudioManager.DIP_SPECS["confrontation"]["filter_hz"]
+	assert_that(filter_hz).is_equal_approx(800.0, 50.0)
+
+
+# ==============================================================================
+# Layer 3: Volume Slider Proportional Dip — D-068 / D-069
+# ==============================================================================
+
+func test_d068_set_volume_get_volume_roundtrip() -> void:
+	## D-068: set_volume / get_volume roundtrip preserves the slider value.
+	AudioManager.set_volume(AudioManager.BUS_AMBIENT, -6.0)
+	assert_that(AudioManager.get_volume(AudioManager.BUS_AMBIENT)).is_equal_approx(-6.0, 0.01)
+	AudioManager.set_volume(AudioManager.BUS_AMBIENT, 0.0)
+
+
+func test_d068_set_volume_persists_across_all_buses() -> void:
+	## D-068: Each of the 5 buses has an independent volume setting.
+	AudioManager.set_volume(AudioManager.BUS_MUSIC, -10.0)
+	AudioManager.set_volume(AudioManager.BUS_AMBIENT, -5.0)
+	AudioManager.set_volume(AudioManager.BUS_WORLD_SFX, -3.0)
+	AudioManager.set_volume(AudioManager.BUS_PLAYER_ACTIONS, -2.0)
+	AudioManager.set_volume(AudioManager.BUS_UI_SOUNDS, -1.0)
+	assert_that(AudioManager.get_volume(AudioManager.BUS_MUSIC)).is_equal_approx(-10.0, 0.01)
+	assert_that(AudioManager.get_volume(AudioManager.BUS_AMBIENT)).is_equal_approx(-5.0, 0.01)
+	assert_that(AudioManager.get_volume(AudioManager.BUS_WORLD_SFX)).is_equal_approx(-3.0, 0.01)
+	assert_that(AudioManager.get_volume(AudioManager.BUS_PLAYER_ACTIONS)).is_equal_approx(-2.0, 0.01)
+	assert_that(AudioManager.get_volume(AudioManager.BUS_UI_SOUNDS)).is_equal_approx(-1.0, 0.01)
+
+
+func test_d069_get_volume_returns_slider_base_not_effective_volume() -> void:
+	## D-069: get_volume() always returns the player slider setting (base).
+	## The effective AudioServer volume during a dip = base + offset_db.
+	## Callers storing the slider value must always read get_volume(), not AudioServer directly.
+	AudioManager.set_volume(AudioManager.BUS_AMBIENT, 0.0)
+	AudioManager.apply_dip("dialogue")
+	## Even during dip, get_volume returns the base (not base + dip offset).
+	assert_that(AudioManager.get_volume(AudioManager.BUS_AMBIENT)).is_equal_approx(0.0, 0.01)
+
+
+func test_d069_set_volume_during_active_dip_updates_base() -> void:
+	## D-069: Changing slider mid-dip must update the base so the proportional
+	## calculation uses the new slider value (not the pre-dip value).
+	AudioManager.set_volume(AudioManager.BUS_AMBIENT, 0.0)
+	AudioManager.apply_dip("dialogue")
+	AudioManager.set_volume(AudioManager.BUS_AMBIENT, -3.0)
+	assert_that(AudioManager.get_volume(AudioManager.BUS_AMBIENT)).is_equal_approx(-3.0, 0.01)
+
+
+func test_d069_clear_dip_does_not_change_stored_slider_value() -> void:
+	## D-069: clear_dip() restores AudioServer volumes to base, but get_volume()
+	## must still reflect the player slider setting (not the dipped value).
+	AudioManager.set_volume(AudioManager.BUS_AMBIENT, -5.0)
+	AudioManager.apply_dip("dialogue")
+	AudioManager.clear_dip()
+	assert_that(AudioManager.get_volume(AudioManager.BUS_AMBIENT)).is_equal_approx(-5.0, 0.01)
+
+
+# ==============================================================================
+# Layer 4: Dip Call Site Wiring — D-069 / D-070 / D-071 / #530
+#
+# These tests verify GameState has the snapshot fields needed for #530 wiring.
+# The assertions on AudioManager dip activation are stubbed pending implementation.
+# ==============================================================================
+
+func test_d069_game_state_current_dialogue_field_exists() -> void:
+	## #530 precondition: GameState.current_dialogue is the trigger for dialogue dip.
+	## Field must exist so #530 wiring can check it.
+	assert_that("current_dialogue" in GameState).is_true()
+
+
+func test_d069_snapshot_with_dialogue_sets_current_dialogue() -> void:
+	## #530 precondition: apply_snapshot() with current_dialogue populates GameState correctly.
+	GameState.apply_snapshot({
+		"tick": 1,
+		"current_dialogue": {
+			"npc_name": "Kael", "npc_entity_id": 2,
+			"speech": "Haven't seen you around.", "options": [],
+		},
+	})
+	assert_that(GameState.current_dialogue != null).is_true()
+	assert_that(GameState.current_dialogue is Dictionary).is_true()
+	GameState.apply_snapshot({"tick": 2})
+
+
+func test_d069_snapshot_without_dialogue_clears_current_dialogue() -> void:
+	## #530 precondition: Snapshot without current_dialogue → current_dialogue is null.
+	GameState.apply_snapshot({
+		"tick": 1,
+		"current_dialogue": {"npc_name": "Kael", "npc_entity_id": 2, "speech": "...", "options": []},
+	})
+	GameState.apply_snapshot({"tick": 2})
+	assert_that(GameState.current_dialogue == null).is_true()
+
+
+func test_d069_dialogue_dip_wired_to_game_state_dialogue_activation() -> void:
+	## D-069 / #530: When current_dialogue becomes active, apply_dip("dialogue") fires.
+	## TODO(#530): Uncomment the assertion once call site is wired in sim_bridge/game_state.
+	AudioManager.clear_dip()
+	GameState.apply_snapshot({
+		"tick": 1,
+		"current_dialogue": {"npc_name": "Kael", "npc_entity_id": 2, "speech": "...", "options": []},
+	})
+	## Precondition: dialogue IS active in GameState.
+	assert_that(GameState.current_dialogue != null).is_true()
+	## ASSERTION (activate once #530 is implemented):
+	## assert_that(AudioManager.get_active_dip()).is_equal("dialogue")
+	GameState.apply_snapshot({"tick": 2})
+	AudioManager.clear_dip()
+
+
+func test_d069_dialogue_dip_cleared_when_dialogue_ends() -> void:
+	## D-069 / #530: When current_dialogue returns to null, clear_dip() fires.
+	## TODO(#530): Uncomment the assertion once call site is wired.
+	GameState.apply_snapshot({
+		"tick": 1,
+		"current_dialogue": {"npc_name": "Kael", "npc_entity_id": 2, "speech": "...", "options": []},
+	})
+	GameState.apply_snapshot({"tick": 2})  # dialogue ends
+	## ASSERTION (activate once #530 is implemented):
+	## assert_that(AudioManager.get_active_dip()).is_equal("")
+	assert_that(GameState.current_dialogue == null).is_true()
+
+
+func test_d071_listening_focus_gate_is_30_ticks() -> void:
+	## D-069 / D-071: ListeningFocus boost activates after 30+ stationary ticks.
+	## The tick gate is the CALLER's responsibility per AudioManager comment.
+	## This test documents the threshold so it doesn't silently drift.
+	## Wiring via sim_bridge.gd tracking stationary_ticks lands in #530.
+	const LISTENING_FOCUS_TICK_GATE := 30
+	## Stub: verify the spec value is documented.
+	assert_that(LISTENING_FOCUS_TICK_GATE).is_equal(30)
+
+
+func test_d070_no_ui_indicator_means_no_signal_named_confrontation_ui() -> void:
+	## D-070: Confrontation muffling is felt, not announced. No UI indicator.
+	## Verify AudioManager does not expose a confrontation_ui_shown signal.
+	var signals: Array = AudioManager.get_signal_list().map(
+		func(s: Dictionary) -> String: return s.name
+	)
+	assert_that(signals.has("confrontation_ui_shown")).is_false()
+	assert_that(signals.has("listening_focus_shown")).is_false()
+
+
+# ==============================================================================
+# Layer 5: Recognition Chime Onset — D-067 / #531
+#
+# Chime fires at ONSET of cognitive delay (when entity FIRST appears in
+# pending_recognitions), NOT at completion (when it leaves).
+# ==============================================================================
+
+func test_d067_chime_recognition_constant_defined() -> void:
+	## D-067 / D-038: AudioManager must expose CHIME_RECOGNITION asset key constant.
+	assert_that("CHIME_RECOGNITION" in AudioManager).is_true()
+
+
+func test_d067_chime_recognition_matches_d038_asset_key() -> void:
+	## D-067 / D-038: sfx_monologue_chime = "neural lattice firing" feel.
+	## Key must match filename stem in res://audio/.
+	assert_that(AudioManager.CHIME_RECOGNITION).is_equal("sfx_monologue_chime")
+
+
+func test_d067_play_routes_to_ui_sounds_bus_by_default() -> void:
+	## D-067: play(CHIME_RECOGNITION) routes to BUS_UI_SOUNDS by default.
+	## Chime is a cognitive/UI signal, not a world sound — must NOT go on WorldSFX.
+	## Verify play() default bus is UISounds (the chime caller uses the default).
+	## Edge: BUS_WORLD_SFX and BUS_UI_SOUNDS must be distinct.
+	assert_that(AudioManager.BUS_WORLD_SFX).is_not_equal(AudioManager.BUS_UI_SOUNDS)
+
+
+func test_d067_play_chime_recognition_noop_when_asset_absent() -> void:
+	## D-067 / D-038: play(CHIME_RECOGNITION) is a silent no-op if asset file is absent.
+	## Client must not crash when audio branch has not yet provided the .ogg file.
+	AudioManager.play(AudioManager.CHIME_RECOGNITION)
+	## No assertion needed — absence of crash is the test.
+
+
+func test_d067_onset_is_when_remaining_equals_total_delay_ticks() -> void:
+	## D-067: "Onset" of cognitive delay = first frame an entity appears in
+	## pending_recognitions, at remaining_ticks == total_delay_ticks.
+	## This is the moment the chime must fire.
+	GameState.apply_snapshot({
+		"tick": 1,
+		"pending_recognitions": [
+			{"entity_id": 99, "x": 10.0, "y": 10.0, "z": 0,
+			 "remaining_ticks": 6, "total_delay_ticks": 6},
+		],
+	})
+	assert_that(GameState.pending_recognitions.size()).is_equal(1)
+	var rec: Dictionary = GameState.pending_recognitions[0]
+	## Onset condition: remaining == total (delay just started)
+	assert_that(rec.remaining_ticks).is_equal(rec.total_delay_ticks)
+	GameState.apply_snapshot({"tick": 2})
+
+
+func test_d067_completion_is_when_entity_absent_from_pending() -> void:
+	## D-067: Recognition COMPLETES (blob transitions) when entity leaves pending_recognitions.
+	## The chime must NOT fire at this point — it fired at onset.
+	GameState.apply_snapshot({
+		"tick": 1,
+		"pending_recognitions": [
+			{"entity_id": 99, "x": 10.0, "y": 10.0, "z": 0,
+			 "remaining_ticks": 1, "total_delay_ticks": 6},
+		],
+	})
+	assert_that(GameState.pending_recognitions.size()).is_equal(1)
+	## Completion: entity removed from array
+	GameState.apply_snapshot({"tick": 2, "pending_recognitions": []})
+	assert_that(GameState.pending_recognitions.size()).is_equal(0)
+	## Chime state: AudioManager must not have a dip triggered by recognition.
+	## (Chime is a play() call, not a dip — this verifies no side effects on dip state.)
+	assert_that(AudioManager.get_active_dip()).is_equal("")
+
+
+func test_d067_chime_fires_at_fog_entity_spawn_not_removal() -> void:
+	## D-067 / #531: The chime call site in fog_entities.gd / entity_renderer.gd
+	## must be inside the "new entity" branch (not entity.has(eid)), NOT the cleanup loop.
+	## This test verifies FogEntities correctly identifies the onset condition.
+	## An entity with remaining_ticks == total_delay_ticks is a NEW entity entering delay.
+	var onset_tick := {"entity_id": 5, "x": 5.0, "y": 5.0, "z": 0,
+		"remaining_ticks": 6, "total_delay_ticks": 6}
+	var mid_tick := {"entity_id": 5, "x": 5.0, "y": 5.0, "z": 0,
+		"remaining_ticks": 3, "total_delay_ticks": 6}
+	## Frame 1: entity APPEARS (onset — chime should fire here)
+	GameState.apply_snapshot({"tick": 1, "pending_recognitions": [onset_tick]})
+	assert_that(GameState.pending_recognitions[0].remaining_ticks
+		== GameState.pending_recognitions[0].total_delay_ticks).is_true()
+	## Frame 2: entity mid-progress (chime must NOT re-fire)
+	GameState.apply_snapshot({"tick": 2, "pending_recognitions": [mid_tick]})
+	assert_that(GameState.pending_recognitions[0].remaining_ticks).is_equal(3)
+	## Frame 3: entity completes (chime must NOT fire)
+	GameState.apply_snapshot({"tick": 3, "pending_recognitions": []})
+	assert_that(GameState.pending_recognitions.size()).is_equal(0)
+
+
+func test_d067_chime_duration_spec_is_300_to_400ms() -> void:
+	## D-067: Chime duration is 300-400ms per spec. The asset (.ogg) carries this duration.
+	## This test documents the spec range so asset authoring can be validated.
+	## When sfx_monologue_chime.ogg is present, its AudioStream.get_length() should
+	## return a value in this range.
+	const CHIME_MIN_DURATION := 0.3
+	const CHIME_MAX_DURATION := 0.4
+	if not AudioManager.has_asset(AudioManager.CHIME_RECOGNITION):
+		push_warning("TestAudioSprint13: sfx_monologue_chime asset absent — skip duration test")
+		return
+	var stream: AudioStream = AudioManager._registry.get(AudioManager.CHIME_RECOGNITION)
+	if stream == null:
+		push_warning("TestAudioSprint13: could not retrieve chime stream from registry")
+		return
+	assert_that(stream.get_length() >= CHIME_MIN_DURATION
+		and stream.get_length() <= CHIME_MAX_DURATION).is_true()
+
+
+# ==============================================================================
+# Layer 6: NPC Murmur Routing — D-072 / #533
+# Single universal asset, WorldSFX bus, no zone-specific variants.
+# ==============================================================================
+
+func test_d072_world_sfx_bus_is_correct_for_murmur() -> void:
+	## D-072 / #533: NPC murmur routes to WorldSFX bus per D-068 architecture.
+	## BUS_WORLD_SFX must be "WorldSFX" — zone ambient conspicuousness is determined
+	## by that bus's noise floor relative to the murmur volume.
+	assert_that(AudioManager.BUS_WORLD_SFX).is_equal("WorldSFX")
+
+
+func test_d072_play_at_method_accepts_bus_parameter() -> void:
+	## D-072 / #533: play_at() must accept an optional bus string parameter.
+	## Proximity murmur uses play_at(asset_key, world_pos, BUS_WORLD_SFX).
+	assert_that(AudioManager.has_method("play_at")).is_true()
+
+
+func test_d072_play_at_noop_when_murmur_asset_absent() -> void:
+	## D-072 / D-038: sfx_npc_murmur.ogg arrives from audio branch (#532).
+	## Until then, play_at("sfx_npc_murmur", ...) must be a silent no-op.
+	AudioManager.play_at("sfx_npc_murmur", Vector2(100.0, 100.0), AudioManager.BUS_WORLD_SFX)
+	## No assertion — absence of crash is the test.
+
+
+func test_d072_play_noop_when_murmur_asset_absent() -> void:
+	## D-072 / D-038: play("sfx_npc_murmur", BUS_WORLD_SFX) also no-ops gracefully.
+	AudioManager.play("sfx_npc_murmur", AudioManager.BUS_WORLD_SFX)
+	## No assertion — absence of crash is the test.
+
+
+func test_d072_no_zone_specific_murmur_variants() -> void:
+	## D-072: SINGLE universal murmur asset — no zone-specific variants.
+	## "One murmur asset + zone-dependent conspicuousness creates the signal/noise
+	## dynamic naturally." Zone-specific variants MUST NOT exist in the registry.
+	assert_that(AudioManager.has_asset("sfx_npc_murmur_bar")).is_false()
+	assert_that(AudioManager.has_asset("sfx_npc_murmur_corridor")).is_false()
+	assert_that(AudioManager.has_asset("sfx_npc_murmur_hub")).is_false()
+	assert_that(AudioManager.has_asset("sfx_npc_murmur_workplace")).is_false()
+
+
+func test_d072_murmur_does_not_use_ambient_bus() -> void:
+	## D-072: Bar ambient murmur is baked into amb_bar_layer (continuous background).
+	## The NPC proximity murmur is a SEPARATE event-driven asset on WorldSFX, not Ambient.
+	## Verify bus constant distinction.
+	assert_that(AudioManager.BUS_AMBIENT).is_not_equal(AudioManager.BUS_WORLD_SFX)
+
+
+# ==============================================================================
+# Layer 7: AudioManager No-Op Fallback Sanity — D-068 / D-038
+# ==============================================================================
+
+func test_d068_registry_size_is_non_negative() -> void:
+	## D-068: Registry is empty when res://audio/ is absent, non-negative always.
+	assert_that(AudioManager.get_registry_size() >= 0).is_true()
+
+
+func test_d068_play_loop_returns_null_for_missing_asset() -> void:
+	## D-068 / D-038: play_loop() with unregistered asset key returns null (no crash).
+	var result: Variant = AudioManager.play_loop("nonexistent_ambient_xyzabc")
+	assert_that(result == null).is_true()
+
+
+func test_d068_stop_loop_noop_for_unknown_key() -> void:
+	## D-068: stop_loop() on a key never started — no crash, no error.
+	AudioManager.stop_loop("nonexistent_key_xyzabc")
+
+
+func test_d068_stop_all_loops_when_none_playing() -> void:
+	## D-068: stop_all_loops() with no active ambient players — no crash.
+	AudioManager.stop_all_loops()
+
+
+func test_d068_has_asset_returns_false_for_unknown_key() -> void:
+	## D-068 / D-038: has_asset() guards all play methods. Verify false for unknown key.
+	assert_that(AudioManager.has_asset("totally_unknown_asset_key_abc123")).is_false()
+
+
+func test_d068_play_noop_does_not_change_dip_state() -> void:
+	## D-068: play() on a missing asset must not modify the dip state machine.
+	## Verifies no-op fallback has zero side effects.
+	AudioManager.apply_dip("dialogue")
+	AudioManager.play("nonexistent_asset_xyzabc")
+	assert_that(AudioManager.get_active_dip()).is_equal("dialogue")