diff --git a/include/boo/audiodev/IAudioSubmix.hpp b/include/boo/audiodev/IAudioSubmix.hpp
index fd28271..8956c67 100644
--- a/include/boo/audiodev/IAudioSubmix.hpp
+++ b/include/boo/audiodev/IAudioSubmix.hpp
@@ -39,9 +39,12 @@ struct IAudioSubmixCallback
     virtual bool canApplyEffect() const=0;
 
     /** Client-provided effect solution for interleaved, master sample-rate audio */
-    virtual void applyEffect(int16_t* audio, const ChannelMap& chanMap, double sampleRate) const=0;
-    virtual void applyEffect(int32_t* audio, const ChannelMap& chanMap, double sampleRate) const=0;
-    virtual void applyEffect(float* audio, const ChannelMap& chanMap, double sampleRate) const=0;
+    virtual void applyEffect(int16_t* audio, size_t frameCount,
+                             const ChannelMap& chanMap, double sampleRate) const=0;
+    virtual void applyEffect(int32_t* audio, size_t frameCount,
+                             const ChannelMap& chanMap, double sampleRate) const=0;
+    virtual void applyEffect(float* audio, size_t frameCount,
+                             const ChannelMap& chanMap, double sampleRate) const=0;
 };
 
 }
diff --git a/lib/audiodev/AudioSubmix.cpp b/lib/audiodev/AudioSubmix.cpp
index ba4c264..6bca5f7 100644
--- a/lib/audiodev/AudioSubmix.cpp
+++ b/lib/audiodev/AudioSubmix.cpp
@@ -39,7 +39,7 @@ void AudioSubmix::_pumpAndMixVoices(size_t frames, int16_t* dataOut)
 
     /* Apply submix effect (if available) */
     if (m_cb && m_cb->canApplyEffect())
-        m_cb->applyEffect(m_scratch16.data(), info.m_channelMap, info.m_sampleRate);
+        m_cb->applyEffect(m_scratch16.data(), frames, info.m_channelMap, info.m_sampleRate);
 
     /* Merge into output mix */
     auto it = m_scratch16.begin();
@@ -72,7 +72,7 @@ void AudioSubmix::_pumpAndMixVoices(size_t frames, int32_t* dataOut)
 
     /* Apply submix effect (if available) */
     if (m_cb && m_cb->canApplyEffect())
-        m_cb->applyEffect(m_scratch32.data(), info.m_channelMap, info.m_sampleRate);
+        m_cb->applyEffect(m_scratch32.data(), frames, info.m_channelMap, info.m_sampleRate);
 
     /* Merge into output mix */
     auto it = m_scratch32.begin();
@@ -105,7 +105,7 @@ void AudioSubmix::_pumpAndMixVoices(size_t frames, float* dataOut)
 
     /* Apply submix effect (if available) */
     if (m_cb && m_cb->canApplyEffect())
-        m_cb->applyEffect(m_scratchFlt.data(), info.m_channelMap, info.m_sampleRate);
+        m_cb->applyEffect(m_scratchFlt.data(), frames, info.m_channelMap, info.m_sampleRate);
 
     /* Merge into output mix */
     auto it = m_scratchFlt.begin();