diff --git a/src/devices/cloud_iii_s_wireless.rs b/src/devices/cloud_iii_s_wireless.rs
index 4400957..510e27d 100644
--- a/src/devices/cloud_iii_s_wireless.rs
+++ b/src/devices/cloud_iii_s_wireless.rs
@@ -55,6 +55,7 @@ const GET_SIDE_TONE_COMMAND_ID: u8 = 0x16;
 const SET_SIDE_TONE_COMMAND_ID: u8 = 0x0D;
 const GET_AUTO_POWER_OFF_COMMAND_ID: u8 = 0x4B;
 const GET_VOICE_PROMPT_COMMAND_ID: u8 = 0x14;
+const SET_VOICE_PROMPT_COMMAND_ID: u8 = 0x0B;
 
 // Button report header (incoming from headset)
 const CONSUMER_CONTROL_HEADER: u8 = 0x0f;
@@ -235,8 +236,13 @@ impl Device for CloudIIISWireless {
         Some(packet)
     }
 
-    fn set_voice_prompt_packet(&self, _enable: bool) -> Option<Vec<u8>> {
-        None
+    fn set_voice_prompt_packet(&self, enable: bool) -> Option<Vec<u8>> {
+        // Confirmed via NGenuity USB capture: `0c 02 03 00 00 0b <0|1>`.
+        let mut packet = BASE_PACKET.to_vec();
+        packet[3] = 0x00;
+        packet[5] = SET_VOICE_PROMPT_COMMAND_ID;
+        packet[6] = enable as u8;
+        Some(packet)
     }
 
     fn get_wireless_connected_status_packet(&self) -> Option<Vec<u8>> {