Android provides the facility to know the incoming number and speak it by the help of android speech api and telephony manager.

Here, we are going to develop a basic android app that speaks the incoming number while phone is in ringing mode.

In the next page, we will see the full version of this app that speaks the caller name and provides the setting option to change the speed rate and pitch. Additionaly, it provides option to add text before and after the incoming number or caller name.

activity_main.xml

We have not done anything special here. It has the simple textview.

File: activity_main.xml
  
    
  
      
  
  
      
  

Activity class

In this activity, we have written the code to know the phone state, and speak the incoming number by the help of TextToSpeech class.

File: MainActivity.java
package com.example.callertalker;  
import java.util.Locale;  
import android.media.AudioManager;  
import android.os.Bundle;  
import android.app.Activity;  
import android.content.Context;  
import android.telephony.PhoneStateListener;  
import android.telephony.TelephonyManager;  
import android.util.Log;  
import android.widget.Toast;  
import android.speech.tts.TextToSpeech;  
  
public class MainActivity extends Activity implements TextToSpeech.OnInitListener {  
    private TextToSpeech tts;  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
          
        tts = new TextToSpeech(this, this);  
            
        TelephonyManager telephonyManager = (TelephonyManager)getSystemService(  
                                                                         Context.TELEPHONY_SERVICE);  
          
        PhoneStateListener callStateListener = new PhoneStateListener() {  
        public void onCallStateChanged(int state, String incomingNumber){  
              if(state==TelephonyManager.CALL_STATE_RINGING){  
                  tts.speak(incomingNumber+" calling", TextToSpeech.QUEUE_FLUSH, null);  
                  Toast.makeText(getApplicationContext(),"Phone is Ringing : "+incomingNumber,   
                                                                               Toast.LENGTH_LONG).show();  
                 }  
              if(state==TelephonyManager.CALL_STATE_OFFHOOK){  
                    Toast.makeText(getApplicationContext(),"Phone in a call or call picked",   
                                                                                  Toast.LENGTH_LONG).show();  
              }  
              if(state==TelephonyManager.CALL_STATE_IDLE){  
                    //phone is neither ringing nor in a call  
              }  
        }  
        };  
        telephonyManager.listen(callStateListener,PhoneStateListener.LISTEN_CALL_STATE);  
    }  
  
    @Override  
    public void onInit(int status) {  
        if (status == TextToSpeech.SUCCESS) {  
            int result = tts.setLanguage(Locale.US);  
            if (result == TextToSpeech.LANG_MISSING_DATA  
                    || result == TextToSpeech.LANG_NOT_SUPPORTED) {  
                Log.e("TTS", "This Language is not supported");  
            } else {          
            }  
  
        } else {  
            Log.e("TTS", "Initilization Failed!");  
        }  
    }  
      
    @Override  
    public void onDestroy() {  
    // Don't forget to shutdown tts!  
    if (tts != null) {  
        tts.stop();  
        tts.shutdown();  
    }  
    super.onDestroy();  
    }  
}

AndroidManifest.xml

You need to add READ_PHONE_STATE uses permission in this xml file. Let’s see the full code.

File: AndroidManifest.xml
  
  
  
      
  
     
       
      
          
              
                  
  
                  
              
          
      
  
  

Output: