diff --git a/src/hci.c b/src/hci.c
index 1a3af5995..0f153ede8 100644
--- a/src/hci.c
+++ b/src/hci.c
@@ -1785,6 +1785,9 @@ void hci_init(hci_transport_t *transport, void *config, bt_control_t *control, r
     hci_stack->ssp_authentication_requirement = SSP_IO_AUTHREQ_MITM_PROTECTION_NOT_REQUIRED_GENERAL_BONDING;
     hci_stack->ssp_auto_accept = 1;
 
+    // voice setting - signed 8 bit pcm data with CVSD over the air
+    hci_stack->sco_voice_setting = 0x40;
+
     hci_state_reset();
 }
 
@@ -2299,8 +2302,7 @@ void hci_run(void){
                 if (connection->address_type == BD_ADDR_TYPE_CLASSIC){
                     hci_send_cmd(&hci_accept_connection_request, connection->address, 1);
                 } else {
-                    // TODO: allows to customize synchronous connection parameters
-                    hci_send_cmd(&hci_accept_synchronous_connection, connection->address, 8000, 8000, 0xFFFF, 0x0060, 0xFF, 0x003F);
+                    hci_send_cmd(&hci_accept_synchronous_connection, connection->address, 8000, 8000, 0xFFFF, hci_stack->sco_voice_setting, 0xFF, 0x003F);
                 }
                 return;
 
@@ -3290,6 +3292,21 @@ void gap_auto_connection_stop_all(void){
 
 #endif
 
+/** 
+ * @brief Configure Voice Setting for use with SCO data in HSP/HFP
+ */
+void hci_set_sco_voice_setting(uint16_t voice_setting){
+    hci_stack->sco_voice_setting = voice_setting;
+}
+
+/**
+ * @brief Get SCO Voice Setting
+ * @return current voice setting
+ */
+uint16_t hci_get_sco_voice_setting(){
+    return hci_stack->sco_voice_setting;
+}
+
 /**
  * @brief Set callback for Bluetooth Hardware Error
  */
diff --git a/src/hci.h b/src/hci.h
index 651428c9f..49639274c 100644
--- a/src/hci.h
+++ b/src/hci.h
@@ -712,6 +712,8 @@ typedef struct {
     /* buffer for scan enable cmd - 0xff no change */
     uint8_t   new_scan_enable_value;
     
+    uint16_t   sco_voice_setting;
+
     // buffer for single connection decline
     uint8_t   decline_reason;
     bd_addr_t decline_addr;
@@ -937,6 +939,17 @@ void hci_le_advertisement_address(uint8_t * addr_type, bd_addr_t addr);
  */
 void hci_set_hardware_error_callback(void (*fn)(void));
 
+/** 
+ * @brief Configure Voice Setting for use with SCO data in HSP/HFP
+ */
+void hci_set_sco_voice_setting(uint16_t voice_setting);
+
+/**
+ * @brief Get SCO Voice Setting
+ * @return current voice setting
+ */
+uint16_t hci_get_sco_voice_setting(void);
+
 /* API_END */
 
 /**