diff --git a/apps/chanora_flutter/ios/Runner/AppDelegate.swift b/apps/chanora_flutter/ios/Runner/AppDelegate.swift
index 6b464ac..5d77b2b 100644
--- a/apps/chanora_flutter/ios/Runner/AppDelegate.swift
+++ b/apps/chanora_flutter/ios/Runner/AppDelegate.swift
@@ -31,44 +31,38 @@ import AVFoundation
       let session = AVAudioSession.sharedInstance()
       try session.setCategory(
         .playAndRecord,
-        mode: .voiceChat,
-        // Category options rationale:
+        mode: .default,
+        // Mode rationale:
         //
-        //   .allowBluetoothHFP  : permit Bluetooth Hands-Free
-        //                         Profile headsets as both input
-        //                         and output. This is the protocol
-        //                         AirPods et al. use for two-way
-        //                         voice. Renamed from .allowBluetooth
-        //                         in iOS 26.
-        //   .allowBluetoothA2DP : permit higher-quality A2DP
-        //                         output-only Bluetooth devices
-        //                         (no mic). Keeping both gives the
-        //                         broadest BT support.
+        // .voiceChat (previously used here) wires the audio session
+        // into iOS's telephony processing pipeline: forced mono
+        // output, automatic gain control, aggressive noise gating,
+        // and \u2014 crucially \u2014 binds the underlying AudioUnit's
+        // output element to a SINGLE physical transducer (the
+        // receiver/earpiece) at session-configure time. The
+        // overrideOutputAudioPort API updates AVAudioSession's
+        // route metadata, but the AudioUnit's output binding is
+        // stale: it keeps routing audio to the originally-bound
+        // hardware. Net symptom: tapping "Speaker" in the picker
+        // flips AVAudioSession.currentRoute.outputs (so our log
+        // says out=Speaker) but no audio comes out the speaker
+        // \u2014 it's still going to the earpiece.
         //
-        // .defaultToSpeaker was REMOVED from this options set after
-        // the user-reported "speaker change not work" bug. With
-        // .voiceChat mode, the framework default output route is
-        // the receiver/earpiece (matches a phone-call UX). Setting
-        // .defaultToSpeaker overrides that to speakerphone by
-        // default \u2014 but then overrideOutputAudioPort(.none) (which
-        // we use when the user picks "iPhone receiver") cannot
-        // restore the receiver because .none simply removes the
-        // speaker OVERRIDE, leaving us back at the .defaultToSpeaker
-        // baseline which is speakerphone. So the "Receiver" picker
-        // option silently no-op'd.
+        // .default mode uses iOS's standard audio graph: stereo
+        // output, no AGC, no telephony post-processing, and the
+        // output AudioUnit re-binds live when the route changes.
+        // This is the same mode Music.app and most non-telephony
+        // apps use. We lose iOS's hardware AEC \u2014 if the user
+        // reports hearing their own voice loop back on speakerphone,
+        // we'll add a software AEC pass on the Rust side (DEC-030
+        // covers the AEC plan).
         //
-        // Without .defaultToSpeaker:
-        //   * Default      = receiver/earpiece  (matches phone UX)
-        //   * overrideOutputAudioPort(.speaker) -> speakerphone
-        //   * overrideOutputAudioPort(.none)    -> back to receiver
-        //   * BT/AirPods connected              -> route follows BT
-        //   * Wired headphones                  -> route follows wire
-        //
-        // Net: every row in our audio output picker now has a
-        // route-change effect that matches its label.
+        // Category options unchanged \u2014 .allowBluetoothHFP +
+        // .allowBluetoothA2DP still permit BT headsets for both
+        // input and output regardless of mode.
         options: [.allowBluetoothHFP, .allowBluetoothA2DP]
       )
-      NSLog("chanora_flutter: AVAudioSession category set (playAndRecord/voiceChat)")
+      NSLog("chanora_flutter: AVAudioSession category set (playAndRecord/default)")
     } catch {
       NSLog("chanora_flutter: AVAudioSession setCategory failed: \(error)")
     }
diff --git a/crates/chanora_audio/src/engine.rs b/crates/chanora_audio/src/engine.rs
index 2e60e65..0bd6b98 100644
--- a/crates/chanora_audio/src/engine.rs
+++ b/crates/chanora_audio/src/engine.rs
@@ -1042,14 +1042,25 @@ where
                             let l = (a_l as f64 + frac * (b_l - a_l) as f64) as f32 * gain;
                             let r = (a_r as f64 + frac * (b_r - a_r) as f64) as f32 * gain;
                             let base = frame_idx * dev_channels;
-                            if dev_channels >= 1 {
+                            if dev_channels == 1 {
+                                // Mono output device (typical on iOS
+                                // .voiceChat / phone-call audio path):
+                                // downmix L+R to a single channel
+                                // rather than dropping the R side.
+                                // Without the downmix, anything panned
+                                // right in the AudioHandler stereo mix
+                                // is silently lost \u2014 on speakerphone
+                                // this manifested as quiet remote
+                                // speakers being inaudible.
+                                out[base] = T::from_f32_sample((l + r) * 0.5);
+                            } else {
                                 out[base] = T::from_f32_sample(l);
-                            }
-                            if dev_channels >= 2 {
-                                out[base + 1] = T::from_f32_sample(r);
-                            }
-                            for c in 2..dev_channels {
-                                out[base + c] = T::from_f32_sample(0.0);
+                                if dev_channels >= 2 {
+                                    out[base + 1] = T::from_f32_sample(r);
+                                }
+                                for c in 2..dev_channels {
+                                    out[base + c] = T::from_f32_sample(0.0);
+                                }
                             }
                             pos += resample_ratio;
                         }