diff --git a/channel_area.go b/channel_area.go
index 6e7389a..a9997f0 100644
--- a/channel_area.go
+++ b/channel_area.go
@@ -18,9 +18,9 @@ import (
 
 // ChannelArea contain sound data.
 type ChannelArea struct {
-	buffer       []byte
-	step         int
-	channelCount int
+	buffer         []byte
+	step           int
+	bytesPerSample int
 }
 
 // fields
@@ -31,9 +31,8 @@ func (a *ChannelArea) Buffer() []byte {
 }
 
 func (a *ChannelArea) bufferWithFrame(frame int) []byte {
-	step := a.step / a.channelCount
 	offset := frame * a.step
-	return a.buffer[offset : offset+step]
+	return a.buffer[offset : offset+a.bytesPerSample]
 }
 
 // Step returns ow many bytes it takes to get from the beginning of one sample to
@@ -42,7 +41,7 @@ func (a *ChannelArea) Step() int {
 	return a.step
 }
 
-func newChannelArea(ptr uintptr, channel int, frameCount int, channelCount int) *ChannelArea {
+func newChannelArea(ptr uintptr, format Format, channel int, frameCount int) *ChannelArea {
 	size := C.sizeof_struct_SoundIoChannelArea
 	areaPtr := ptr + uintptr(channel*size)
 	area := (*C.struct_SoundIoChannelArea)(unsafe.Pointer(areaPtr))
@@ -57,8 +56,8 @@ func newChannelArea(ptr uintptr, channel int, frameCount int, channelCount int)
 	buffer := *(*[]byte)(unsafe.Pointer(sh))
 
 	return &ChannelArea{
-		buffer:       buffer,
-		step:         areaStep,
-		channelCount: channelCount,
+		buffer:         buffer,
+		step:           areaStep,
+		bytesPerSample: BytesPerSample(format),
 	}
 }
diff --git a/channel_areas.go b/channel_areas.go
index 6f27e6a..699a4e2 100644
--- a/channel_areas.go
+++ b/channel_areas.go
@@ -40,14 +40,14 @@ func (a *ChannelAreas) Area(channel int) *ChannelArea {
 // Buffer returns ChannelArea buffer.
 func (a *ChannelAreas) Buffer(channel int, frame int) []byte {
 	return a.areas[channel].bufferWithFrame(frame)
-
 }
-func newChannelAreas(ptr *C.struct_SoundIoChannelArea, chanelCount int, frameCount int) *ChannelAreas {
+
+func newChannelAreas(ptr *C.struct_SoundIoChannelArea, format Format, chanelCount int, frameCount int) *ChannelAreas {
 	areasPtr := uintptr(unsafe.Pointer(ptr))
 	areas := make([]*ChannelArea, chanelCount)
 
 	for ch := 0; ch < chanelCount; ch++ {
-		areas[ch] = newChannelArea(areasPtr, ch, frameCount, chanelCount)
+		areas[ch] = newChannelArea(areasPtr, format, ch, frameCount)
 	}
 
 	return &ChannelAreas{
diff --git a/examples/sio_sine/main.go b/examples/sio_sine/main.go
index f3ac2c4..2888f5d 100644
--- a/examples/sio_sine/main.go
+++ b/examples/sio_sine/main.go
@@ -11,7 +11,7 @@ import (
 	"context"
 	"encoding/binary"
 	"fmt"
-	"github.com/crow-misia/go-libsoundio"
+	soundio "github.com/crow-misia/go-libsoundio"
 	"log"
 	"math"
 	"os"
@@ -177,7 +177,7 @@ func realMain(ctx context.Context) error {
 	log.Printf("    Layout Error = %s", outStream.LayoutError())
 
 	log.Printf("    Name = %s", outStream.Name())
-	log.Printf("    BytePerFrame = %d", outStream.BytesPerSample())
+	log.Printf("    BytePerFrame = %d", outStream.BytesPerFrame())
 	log.Printf("    BytePerSample = %d", outStream.BytesPerSample())
 	log.Printf("    SoftwareLatency = %f", outStream.SoftwareLatency())
 	log.Printf("    SampleRate = %d", outStream.SampleRate())
diff --git a/in_stream.go b/in_stream.go
index 25f5d56..60d63c8 100644
--- a/in_stream.go
+++ b/in_stream.go
@@ -176,7 +176,7 @@ func (s *InStream) BeginRead(frameCount *int) (*ChannelAreas, error) {
 	if ptrs == nil {
 		return nil, nil
 	}
-	return newChannelAreas(ptrs, s.Layout().ChannelCount(), *frameCount), nil
+	return newChannelAreas(ptrs, s.Format(), s.Layout().ChannelCount(), *frameCount), nil
 }
 
 // EndRead will drop all of the frames from when you called.
diff --git a/out_stream.go b/out_stream.go
index 4a84b52..2c381ef 100644
--- a/out_stream.go
+++ b/out_stream.go
@@ -188,7 +188,7 @@ func (s *OutStream) BeginWrite(frameCount *int) (*ChannelAreas, error) {
 	if ptrs == nil {
 		return nil, nil
 	}
-	return newChannelAreas(ptrs, s.Layout().ChannelCount(), *frameCount), nil
+	return newChannelAreas(ptrs, s.Format(), s.Layout().ChannelCount(), *frameCount), nil
 }
 
 // EndWrite commits the write that you began with BeginWrite.