diff --git a/fuzz/dfuzz.cc b/fuzz/dfuzz.cc
index c926d61..29e6b57 100644
--- a/fuzz/dfuzz.cc
+++ b/fuzz/dfuzz.cc
@@ -23,20 +23,21 @@ using namespace lc3;
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
 {
-  const int dt_list[] = { 7500, 10000 };
-  const int sr_list[] = { 8000, 16000, 24000, 32000, 48000 };
+  const int dt_list[] = { 2500, 5000, 7500, 10000 };
+  const int sr_list[] = { 8000, 16000, 24000, 32000, 48000, 96000 };
 
   FuzzedDataProvider fdp(data, size);
 
   int dt_us = fdp.PickValueInArray(dt_list);
   int sr_hz = fdp.PickValueInArray(sr_list);
   int nchannels =fdp.PickValueInArray({1, 2});
+  bool hrmode = fdp.ConsumeBool();
 
   int sr_pcm_hz = fdp.PickValueInArray(sr_list);
   if (sr_pcm_hz < sr_hz)
     sr_pcm_hz = 0;
 
-  Decoder dec(dt_us, sr_hz, sr_pcm_hz, nchannels);
+  Decoder dec(dt_us, sr_hz, sr_pcm_hz, nchannels, hrmode);
 
   int frame_size = fdp.ConsumeIntegralInRange(
     LC3_MIN_FRAME_BYTES, LC3_MAX_FRAME_BYTES);
@@ -46,6 +47,8 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
       PcmFormat::kS24In3Le, PcmFormat::kF32 });
 
   int frame_samples = dec.GetFrameSamples();
+  if (frame_samples < 0)
+      return -1;
 
   int sample_bytes =
     fmt == PcmFormat::kS16 ? sizeof(int16_t) :
diff --git a/fuzz/efuzz.cc b/fuzz/efuzz.cc
index e79ef9c..be68b9c 100644
--- a/fuzz/efuzz.cc
+++ b/fuzz/efuzz.cc
@@ -70,7 +70,7 @@ int encode(Encoder &e, int frame_size, int nchannels,
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
 {
-  const int dt_list[] = { 7500, 10000 };
+  const int dt_list[] = { 2500, 5000, 7500, 10000 };
   const int sr_list[] = { 8000, 16000, 24000, 32000, 48000 };
 
   FuzzedDataProvider fdp(data, size);
@@ -78,12 +78,13 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
   int dt_us = fdp.PickValueInArray(dt_list);
   int sr_hz = fdp.PickValueInArray(sr_list);
   int nchannels = fdp.PickValueInArray({1, 2});
+  bool hrmode = fdp.ConsumeBool();
 
   int sr_pcm_hz = fdp.PickValueInArray(sr_list);
   if (sr_pcm_hz < sr_hz)
     sr_pcm_hz = 0;
 
-  Encoder enc(dt_us, sr_hz, sr_pcm_hz, nchannels);
+  Encoder enc(dt_us, sr_hz, sr_pcm_hz, nchannels, hrmode);
 
   PcmFormat fmt = fdp.PickValueInArray(
     { PcmFormat::kS16, PcmFormat::kS24,