diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 38c9687..0df9a39 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -1193,25 +1193,10 @@
         String8 value;
         if (param.get(String8(AudioParameter::keyBtNrec), value) == NO_ERROR) {
             bool btNrecIsOff = (value == AudioParameter::valueOff);
-            if (mBtNrecIsOff != btNrecIsOff) {
+            if (mBtNrecIsOff.exchange(btNrecIsOff) != btNrecIsOff) {
                 for (size_t i = 0; i < mRecordThreads.size(); i++) {
-                    sp<RecordThread> thread = mRecordThreads.valueAt(i);
-                    audio_devices_t device = thread->inDevice();
-                    bool suspend = audio_is_bluetooth_sco_device(device) && btNrecIsOff;
-                    // collect all of the thread's session IDs
-                    KeyedVector<audio_session_t, bool> ids = thread->sessionIds();
-                    // suspend effects associated with those session IDs
-                    for (size_t j = 0; j < ids.size(); ++j) {
-                        audio_session_t sessionId = ids.keyAt(j);
-                        thread->setEffectSuspended(FX_IID_AEC,
-                                                   suspend,
-                                                   sessionId);
-                        thread->setEffectSuspended(FX_IID_NS,
-                                                   suspend,
-                                                   sessionId);
-                    }
+                    mRecordThreads.valueAt(i)->checkBtNrec();
                 }
-                mBtNrecIsOff = btNrecIsOff;
             }
         }
         String8 screenState;
@@ -3214,6 +3199,11 @@
 
 status_t AudioFlinger::putOrphanEffectChain_l(const sp<AudioFlinger::EffectChain>& chain)
 {
+    // clear possible suspended state before parking the chain so that it starts in default state
+    // when attached to a new record thread
+    chain->setEffectSuspended_l(FX_IID_AEC, false);
+    chain->setEffectSuspended_l(FX_IID_NS, false);
+
     audio_session_t session = chain->sessionId();
     ssize_t index = mOrphanEffectChains.indexOfKey(session);
     ALOGV("putOrphanEffectChain_l session %d index %zd", session, index);
diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index 8a96c1d..9023b2d 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -350,12 +350,13 @@
                                         sync_event_callback_t callBack,
                                         const wp<RefBase>& cookie);
 
+    bool        btNrecIsOff() const { return mBtNrecIsOff.load(); }
+
+
 private:
 
                audio_mode_t getMode() const { return mMode; }
 
-                bool        btNrecIsOff() const { return mBtNrecIsOff; }
-
                             AudioFlinger() ANDROID_API;
     virtual                 ~AudioFlinger();
 
@@ -781,7 +782,7 @@
                 volatile atomic_uint_fast32_t       mNextUniqueIds[AUDIO_UNIQUE_ID_USE_MAX];
 
                 audio_mode_t                        mMode;
-                bool                                mBtNrecIsOff;
+                std::atomic_bool                    mBtNrecIsOff;
 
                 // protected by mLock
                 Vector<AudioSessionRef*> mAudioSessionRefs;
diff --git a/services/audioflinger/Effects.cpp b/services/audioflinger/Effects.cpp
index f4428fe..f2c1c4f 100644
--- a/services/audioflinger/Effects.cpp
+++ b/services/audioflinger/Effects.cpp
@@ -21,10 +21,12 @@
 
 #include "Configuration.h"
 #include <utils/Log.h>
+#include <system/audio_effects/effect_aec.h>
+#include <system/audio_effects/effect_ns.h>
+#include <system/audio_effects/effect_visualizer.h>
 #include <audio_utils/primitives.h>
 #include <media/audiohal/EffectHalInterface.h>
 #include <media/audiohal/EffectsFactoryHalInterface.h>
-#include <system/audio_effects/effect_visualizer.h>
 
 #include "AudioFlinger.h"
 #include "ServiceUtilities.h"
@@ -1809,6 +1811,7 @@
                 idx_insert);
     }
     effect->configure();
+
     return NO_ERROR;
 }
 
@@ -2030,6 +2033,7 @@
             mSuspendedEffects.add(type->timeLow, desc);
             ALOGV("setEffectSuspended_l() add entry for %08x", type->timeLow);
         }
+
         if (desc->mRefCount++ == 0) {
             sp<EffectModule> effect = getEffectIfEnabled(type);
             if (effect != 0) {
@@ -2045,7 +2049,8 @@
         desc = mSuspendedEffects.valueAt(index);
         if (desc->mRefCount <= 0) {
             ALOGW("setEffectSuspended_l() restore refcount should not be 0 %d", desc->mRefCount);
-            desc->mRefCount = 1;
+            desc->mRefCount = 0;
+            return;
         }
         if (--desc->mRefCount == 0) {
             ALOGV("setEffectSuspended_l() remove entry for %08x", mSuspendedEffects.keyAt(index));
@@ -2123,6 +2128,17 @@
 const effect_uuid_t * const SL_IID_VOLUME = &SL_IID_VOLUME_;
 #endif //OPENSL_ES_H_
 
+/* static */
+bool AudioFlinger::EffectChain::isEffectEligibleForBtNrecSuspend(const effect_uuid_t *type)
+{
+    // Only NS and AEC are suspended when BtNRec is off
+    if ((memcmp(type, FX_IID_AEC, sizeof(effect_uuid_t)) == 0) ||
+        (memcmp(type, FX_IID_NS, sizeof(effect_uuid_t)) == 0)) {
+        return true;
+    }
+    return false;
+}
+
 bool AudioFlinger::EffectChain::isEffectEligibleForSuspend(const effect_descriptor_t& desc)
 {
     // auxiliary effects and visualizer are never suspended on output mix
@@ -2177,7 +2193,7 @@
         ALOGV("checkSuspendOnEffectEnabled() enable suspending fx %08x",
             effect->desc().type.timeLow);
         sp<SuspendedEffectDesc> desc = mSuspendedEffects.valueAt(index);
-        // if effect is requested to suspended but was not yet enabled, supend it now.
+        // if effect is requested to suspended but was not yet enabled, suspend it now.
         if (desc->mEffect == 0) {
             desc->mEffect = effect;
             effect->setEnabled(false);
diff --git a/services/audioflinger/Effects.h b/services/audioflinger/Effects.h
index e37529e..e29798b 100644
--- a/services/audioflinger/Effects.h
+++ b/services/audioflinger/Effects.h
@@ -331,7 +331,8 @@
     void setStrategy(uint32_t strategy)
             { mStrategy = strategy; }
 
-    // suspend effect of the given type
+    // suspend or restore effects of the specified type. The number of suspend requests is counted
+    // and restore occurs once all suspend requests are cancelled.
     void setEffectSuspended_l(const effect_uuid_t *type,
                               bool suspend);
     // suspend all eligible effects
@@ -372,7 +373,7 @@
     public:
         SuspendedEffectDesc() : mRefCount(0) {}
 
-        int mRefCount;
+        int mRefCount;   // > 0 when suspended
         effect_uuid_t mType;
         wp<EffectModule> mEffect;
     };
@@ -388,6 +389,8 @@
     // types or implementations from the suspend/restore mechanism.
     bool isEffectEligibleForSuspend(const effect_descriptor_t& desc);
 
+    static bool isEffectEligibleForBtNrecSuspend(const effect_uuid_t *type);
+
     void clearInputBuffer_l(const sp<ThreadBase>& thread);
 
     void setThread(const sp<ThreadBase>& thread);
@@ -414,6 +417,6 @@
              // mSuspendedEffects lists all effects currently suspended in the chain.
              // Use effect type UUID timelow field as key. There is no real risk of identical
              // timeLow fields among effect type UUIDs.
-             // Updated by updateSuspendedSessions_l() only.
+             // Updated by setEffectSuspended_l() and setEffectSuspendedAll_l() only.
              KeyedVector< int, sp<SuspendedEffectDesc> > mSuspendedEffects;
 };
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index d932483..a67acd6 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -991,13 +991,6 @@
     ALOGW("power manager service died !!!");
 }
 
-void AudioFlinger::ThreadBase::setEffectSuspended(
-        const effect_uuid_t *type, bool suspend, audio_session_t sessionId)
-{
-    Mutex::Autolock _l(mLock);
-    setEffectSuspended_l(type, suspend, sessionId);
-}
-
 void AudioFlinger::ThreadBase::setEffectSuspended_l(
         const effect_uuid_t *type, bool suspend, audio_session_t sessionId)
 {
@@ -1451,6 +1444,7 @@
     effect->setDevice(mInDevice);
     effect->setMode(mAudioFlinger->getMode());
     effect->setAudioSource(mAudioSource);
+
     return NO_ERROR;
 }
 
@@ -5947,6 +5941,7 @@
     // mPipeMemory
     // mFastCaptureNBLogWriter
     , mFastTrackAvail(false)
+    , mBtNrecSuspended(false)
 {
     snprintf(mThreadName, kThreadNameLength, "AudioIn_%X", id);
     mNBLogWriter = audioFlinger->newWriter_l(kLogSize, mThreadName);
@@ -6711,12 +6706,6 @@
         }
         mTracks.add(track);
 
-        // disable AEC and NS if the device is a BT SCO headset supporting those pre processings
-        bool suspend = audio_is_bluetooth_sco_device(mInDevice) &&
-                        mAudioFlinger->btNrecIsOff();
-        setEffectSuspended_l(FX_IID_AEC, suspend, sessionId);
-        setEffectSuspended_l(FX_IID_NS, suspend, sessionId);
-
         if ((*flags & AUDIO_INPUT_FLAG_FAST) && (tid != -1)) {
             pid_t callingPid = IPCThreadState::self()->getCallingPid();
             // we don't have CAP_SYS_NICE, nor do we want to have it as it's too powerful,
@@ -7079,6 +7068,26 @@
     buffer->frameCount = 0;
 }
 
+void AudioFlinger::RecordThread::checkBtNrec()
+{
+    Mutex::Autolock _l(mLock);
+    checkBtNrec_l();
+}
+
+void AudioFlinger::RecordThread::checkBtNrec_l()
+{
+    // disable AEC and NS if the device is a BT SCO headset supporting those
+    // pre processings
+    bool suspend = audio_is_bluetooth_sco_device(mInDevice) &&
+                        mAudioFlinger->btNrecIsOff();
+    if (mBtNrecSuspended.exchange(suspend) != suspend) {
+        for (size_t i = 0; i < mEffectChains.size(); i++) {
+            setEffectSuspended_l(FX_IID_AEC, suspend, mEffectChains[i]->sessionId());
+            setEffectSuspended_l(FX_IID_NS, suspend, mEffectChains[i]->sessionId());
+        }
+    }
+}
+
 
 bool AudioFlinger::RecordThread::checkForNewParameter_l(const String8& keyValuePair,
                                                         status_t& status)
@@ -7151,17 +7160,7 @@
             if (value != AUDIO_DEVICE_NONE) {
                 mPrevInDevice = value;
             }
-            // disable AEC and NS if the device is a BT SCO headset supporting those
-            // pre processings
-            if (mTracks.size() > 0) {
-                bool suspend = audio_is_bluetooth_sco_device(mInDevice) &&
-                                    mAudioFlinger->btNrecIsOff();
-                for (size_t i = 0; i < mTracks.size(); i++) {
-                    sp<RecordTrack> track = mTracks[i];
-                    setEffectSuspended_l(FX_IID_AEC, suspend, track->sessionId());
-                    setEffectSuspended_l(FX_IID_NS, suspend, track->sessionId());
-                }
-            }
+            checkBtNrec_l();
         }
     }
     if (param.getInt(String8(AudioParameter::keyInputSource), value) == NO_ERROR &&
@@ -7394,17 +7393,7 @@
         mEffectChains[i]->setDevice_l(mInDevice);
     }
 
-    // disable AEC and NS if the device is a BT SCO headset supporting those
-    // pre processings
-    if (mTracks.size() > 0) {
-        bool suspend = audio_is_bluetooth_sco_device(mInDevice) &&
-                            mAudioFlinger->btNrecIsOff();
-        for (size_t i = 0; i < mTracks.size(); i++) {
-            sp<RecordTrack> track = mTracks[i];
-            setEffectSuspended_l(FX_IID_AEC, suspend, track->sessionId());
-            setEffectSuspended_l(FX_IID_NS, suspend, track->sessionId());
-        }
-    }
+    checkBtNrec_l();
 
     // store new source and send to effects
     if (mAudioSource != patch->sinks[0].ext.mix.usecase.source) {
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index 65266b0..062bad6 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -361,11 +361,6 @@
                 virtual uint32_t getStrategyForSession_l(audio_session_t sessionId __unused)
                         { return 0; }
 
-                // suspend or restore effect according to the type of effect passed. a NULL
-                // type pointer means suspend all effects in the session
-                void setEffectSuspended(const effect_uuid_t *type,
-                                        bool suspend,
-                                        audio_session_t sessionId = AUDIO_SESSION_OUTPUT_MIX);
                 // check if some effects must be suspended/restored when an effect is enabled
                 // or disabled
                 void checkSuspendOnEffectEnabled(const sp<EffectModule>& effect,
@@ -417,10 +412,13 @@
                 void        releaseWakeLock_l();
                 void        updateWakeLockUids_l(const SortedVector<uid_t> &uids);
                 void        getPowerManager_l();
+                // suspend or restore effects of the specified type (or all if type is NULL)
+                // on a given session. The number of suspend requests is counted and restore
+                // occurs when all suspend requests are cancelled.
                 void setEffectSuspended_l(const effect_uuid_t *type,
                                           bool suspend,
                                           audio_session_t sessionId);
-                // updated mSuspendedSessions when an effect suspended or restored
+                // updated mSuspendedSessions when an effect is suspended or restored
                 void        updateSuspendedSessions_l(const effect_uuid_t *type,
                                                       bool suspend,
                                                       audio_session_t sessionId);
@@ -484,6 +482,7 @@
                 const sp<PMDeathRecipient> mDeathRecipient;
                 // list of suspended effects per session and per type. The first (outer) vector is
                 // keyed by session ID, the second (inner) by type UUID timeLow field
+                // Updated by updateSuspendedSessions_l() only.
                 KeyedVector< audio_session_t, KeyedVector< int, sp<SuspendedSessionDesc> > >
                                         mSuspendedSessions;
                 static const size_t     kLogSize = 4 * 1024;
@@ -1387,6 +1386,8 @@
                         }
     virtual bool        isOutput() const override { return false; }
 
+            void        checkBtNrec();
+
 private:
             // Enter standby if not already in standby, and set mStandby flag
             void    standbyIfNotAlreadyInStandby();
@@ -1394,6 +1395,8 @@
             // Call the HAL standby method unconditionally, and don't change mStandby flag
             void    inputStandBy();
 
+            void    checkBtNrec_l();
+
             AudioStreamIn                       *mInput;
             SortedVector < sp<RecordTrack> >    mTracks;
             // mActiveTracks has dual roles:  it indicates the current active track(s), and
@@ -1453,6 +1456,8 @@
             sp<NBLog::Writer>                   mFastCaptureNBLogWriter;
 
             bool                                mFastTrackAvail;    // true if fast track available
+            // common state to all record threads
+            std::atomic_bool                    mBtNrecSuspended;
 };
 
 class MmapThread : public ThreadBase