diff --git a/apps/chanora_flutter/ios/Runner/AppDelegate.swift b/apps/chanora_flutter/ios/Runner/AppDelegate.swift
index b3d7415..ce11818 100644
--- a/apps/chanora_flutter/ios/Runner/AppDelegate.swift
+++ b/apps/chanora_flutter/ios/Runner/AppDelegate.swift
@@ -153,6 +153,28 @@ import AVFoundation
     do {
       try AVAudioSession.sharedInstance().setActive(true, options: [])
       NSLog("chanora_flutter: AVAudioSession activated on foreground")
+      // Read back the ACTUAL session state. preferredSampleRate /
+      // preferredIOBufferDuration are hints; iOS may pick something
+      // else depending on hardware + currently-engaged effects.
+      // Without these we can't tell whether VPIO is running at
+      // 48 kHz mono (what our render callback assumes) or at e.g.
+      // 44.1 kHz (which would explain the user's broken playback
+      // \u2014 our render callback would be writing samples at the
+      // wrong rate, causing pitch + timing artifacts).
+      let s = AVAudioSession.sharedInstance()
+      let route = s.currentRoute
+      let outs = route.outputs.map { "\($0.portType.rawValue)/\($0.portName)" }.joined(separator: ",")
+      let ins = route.inputs.map { "\($0.portType.rawValue)/\($0.portName)" }.joined(separator: ",")
+      NSLog(
+        "chanora_flutter: AVAudioSession actual: " +
+        "category=\(s.category.rawValue) " +
+        "mode=\(s.mode.rawValue) " +
+        "sampleRate=\(s.sampleRate) " +
+        "ioBufferDuration=\(String(format: "%.4f", s.ioBufferDuration)) " +
+        "outputs=[\(outs)] " +
+        "inputs=[\(ins)] " +
+        "outputVolume=\(s.outputVolume)"
+      )
     } catch {
       NSLog("chanora_flutter: AVAudioSession setActive failed: \(error)")
     }
diff --git a/apps/chanora_flutter/pubspec.yaml b/apps/chanora_flutter/pubspec.yaml
index 71e63ab..2ca8cf0 100644
--- a/apps/chanora_flutter/pubspec.yaml
+++ b/apps/chanora_flutter/pubspec.yaml
@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 1.0.0-rc.8+70
+version: 1.0.0-rc.8+71
 
 environment:
   sdk: ^3.11.5
diff --git a/crates/chanora_audio/src/ios_voice_unit.rs b/crates/chanora_audio/src/ios_voice_unit.rs
index bcb5884..d95397e 100644
--- a/crates/chanora_audio/src/ios_voice_unit.rs
+++ b/crates/chanora_audio/src/ios_voice_unit.rs
@@ -579,6 +579,48 @@ impl IosVoiceUnit {
             "ios VPIO audio unit started"
         );
 
+        // Read back the ACTUAL stream format VPIO accepted on each
+        // bus (iOS sometimes substitutes its own format if the
+        // hardware can't satisfy our preference) and the actual
+        // AVAudioSession sample rate + IO buffer duration. Without
+        // these we can't tell whether our 48 kHz Int16 mono format
+        // was honoured or silently downgraded to e.g. 44.1 kHz
+        // Float32 (which would cause our render callback to write
+        // i16 values into a buffer iOS interprets as f32 = severe
+        // distortion). Diagnostic prompted by external review
+        // pointing out that 'preferredSampleRate' is a hint, not
+        // a guarantee \u2014 must verify post-init.
+        match unit.output_stream_format() {
+            Ok(fmt) => info!(
+                target: "chanora_audio",
+                sample_rate = fmt.sample_rate,
+                channels = fmt.channels,
+                sample_format = ?fmt.sample_format,
+                flags = ?fmt.flags,
+                "ios VPIO actual OUTPUT stream format (post-init)"
+            ),
+            Err(e) => warn!(
+                target: "chanora_audio",
+                error = %e,
+                "ios VPIO output_stream_format read failed"
+            ),
+        }
+        match unit.input_stream_format() {
+            Ok(fmt) => info!(
+                target: "chanora_audio",
+                sample_rate = fmt.sample_rate,
+                channels = fmt.channels,
+                sample_format = ?fmt.sample_format,
+                flags = ?fmt.flags,
+                "ios VPIO actual INPUT stream format (post-init)"
+            ),
+            Err(e) => warn!(
+                target: "chanora_audio",
+                error = %e,
+                "ios VPIO input_stream_format read failed"
+            ),
+        }
+
         Ok(Self { unit })
     }
 }