MainActivity.java

package com.fathasss.speech_to_text;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.speech.RecognizerIntent;
import android.view.View;
import android.widget.ImageButton;
import android.widget.TextView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.Locale;

public class MainActivity extends AppCompatActivity {

    private static final int REQUEST_CODE_SPEECH_INPUT = 1000;
    TextView mTextView;
    ImageButton mImageButton;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mTextView = findViewById(R.id.textView);
        mImageButton = findViewById(R.id.image);

        mImageButton.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                speak();
            }
        });
    }
    private void speak(){
        Intent intent= new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
        intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL,RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
        intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE, Locale.getDefault());
        intent.putExtra(RecognizerIntent.EXTRA_PROMPT, "Merhaba. Hemen konuşmaya başla :)");
        try{
            startActivityForResult(intent, REQUEST_CODE_SPEECH_INPUT);
        }
        catch(Exception ex){
            Toast.makeText(this,""+ ex.getMessage(),Toast.LENGTH_SHORT).show();
        }
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch(requestCode){
            case REQUEST_CODE_SPEECH_INPUT:{
                if(resultCode == RESULT_OK && null!=data){
                    ArrayList<String> result= data.getStringArrayListExtra(RecognizerIntent.EXTRA_RESULTS);
                    mTextView.setText(result.get(0));
                }
                break;
            }
        }
    }
}