Getting error "Unable to load Voice Directory" to automate Voice Search

Question

I am using freetts library to automate the voice search. But my speakUtil.java is failing and giving error : "FAILED CONFIGURATION: @BeforeClass setup java.lang.Error: Unable to load voice directory. java.lang.ClassNotFoundException: com.sun.speech.freetts.en.us.cmu_us_kal.KevinVoiceDirectory"

I have searched multiple threads related to this but they all tell to add the freetts jar files in lib folder in netbeans, but nothing related to eclipse which I am using.

This is my speakUtil.java class:

public class speakUtil {
        static com.sun.speech.freetts.Voice systemVoice = null;
        
        public static void allocate(){
            System.setProperty("freetts.voices", "com.sun.speech.freetts.en.us.cmu_us_kal.KevinVoiceDirectory");
            systemVoice = VoiceManager.getInstance().getVoice("kevin16");
            systemVoice.allocate();
        }
        
        public static void speak(String text){
            systemVoice.speak(text);
        }
        
        public static void deallocate(){
            systemVoice.deallocate();
        }
    }

This is my selenium test

public class voiceSearchTest {
    
    @BeforeClass
  public void setup(){
    speakUtil.allocate(); //activating speakUtil before test runs
  }
    
    
    @Test(dataProvider = "voiceSearch")
    public void voiceSearch(String searchText) throws InterruptedException {

        //code for dealing with Allow mic popup 

        HashMap<String, Integer> conentSettings = new HashMap<String, Integer>();
        HashMap<String, Object> profile = new HashMap<String, Object>();
        HashMap<String, Object> prefs = new HashMap<String, Object>();
        
        conentSettings.put("media_stream", 1);
        profile.put("managed_default_content_settings", conentSettings);
        prefs.put("profile", profile);
        ChromeOptions options = new ChromeOptions();
        options.setExperimentalOption("prefs", prefs);      
        
//calling chromedriver
        WebDriverManager.chromedriver().setup();
        WebDriver driver = new ChromeDriver(options);
        
        driver.manage().timeouts().implicitlyWait(Duration.ofSeconds(10));
        
        driver.get("https://example.com/");
        driver.manage().window().maximize();
        Thread.sleep(5000);
        
//creating object to call voice search
             pageobjects.voiceSearch voicesearch = new  
             pageobjects.voiceSearch(driver);
        
        
        voicesearch.searchClick(); //clicking on search icon
        voicesearch.voiceClick(); //clicking on voice search icon
        speakUtil.speak(searchText); //speaking text from dataprovider
        
        voicesearch.startListening(); //listening to voice
        voicesearch.startListening();
        voicesearch.getVoiceSearchText(); //getting spoken voice to validate if same words are being entered as the one spoken.
        
        
        
    }
    
    @DataProvider(name = "voiceSearch")
  public Object[][] voiceSearch2(){
        return new Object[][] {
             {"Good Boy"},
            
        };
      }
    
     @AfterClass
      public void deallocate(){
        speakUtil.deallocate(); //deallocating speakUtil.java
      }
}