diff --git a/src/backends/appkit.rs b/src/backends/appkit.rs
index 3df4bfb..e9beb67 100644
--- a/src/backends/appkit.rs
+++ b/src/backends/appkit.rs
@@ -209,7 +209,7 @@ impl Backend for AppKit {
         unimplemented!()
     }
 
-    fn set_voice(&mut self, voice: &Voice) -> Result<(), Error> {
+    fn set_voice(&mut self, _voice: &Voice) -> Result<(), Error> {
         unimplemented!()
     }
 }
diff --git a/src/backends/av_foundation/voices.rs b/src/backends/av_foundation/voices.rs
deleted file mode 100644
index 3df9b69..0000000
--- a/src/backends/av_foundation/voices.rs
+++ /dev/null
@@ -1,67 +0,0 @@
-use cocoa_foundation::base::{id, nil};
-use cocoa_foundation::foundation::NSString;
-use core_foundation::array::CFArray;
-use core_foundation::string::CFString;
-use objc::runtime::*;
-use objc::*;
-
-use crate::backends::AvFoundation;
-
-#[derive(Copy, Clone, Debug)]
-pub(crate) struct AVSpeechSynthesisVoice(*const Object);
-
-impl AVSpeechSynthesisVoice {
-    pub fn new() -> Self {
-        let voice: *const Object;
-        unsafe {
-            voice = msg_send![class!(AVSpeechSynthesisVoice), new];
-        };
-        AVSpeechSynthesisVoice { 0: voice }
-    }
-}
-
-/*impl voices::Backend for AVSpeechSynthesisVoice {
-    type Backend = AvFoundation;
-
-    fn from_id(id: String) -> Self {
-        unimplemented!()
-    }
-
-    fn from_language(lang: voices::LanguageIdentifier) -> Self {
-        unimplemented!()
-    }
-
-    fn list() -> Vec<Self> {
-        let voices: CFArray = unsafe { msg_send![class!(AVSpeechSynthesisVoice), speechVoices] };
-        voices
-            .iter()
-            .map(|v| AVSpeechSynthesisVoice {
-                0: *v as *const Object,
-            })
-            .collect()
-    }
-
-    fn name(self) -> String {
-        let name: CFString = unsafe { msg_send![self.0, name] };
-        name.to_string()
-    }
-
-    fn gender(self) -> Gender {
-        let gender: i64 = unsafe { msg_send![self.0, gender] };
-        match gender {
-            1 => Gender::Male,
-            2 => Gender::Female,
-            _ => Gender::Other,
-        }
-    }
-
-    fn id(self) -> String {
-        let identifier: CFString = unsafe { msg_send![self.0, identifier] };
-        identifier.to_string()
-    }
-
-    fn language(self) -> voices::LanguageIdentifier {
-        let lang: CFString = unsafe { msg_send![self.0, language] };
-        lang.to_string().parse().unwrap()
-    }
-}*/