在Android上实现实时电话字幕和转录可以使用Android的SpeechRecognizer API和TelephonyManager API。

以下是这个问题的代码示例：

1. 在AndroidManifest.xml添加权限：

2. 在Activity中实现TelephonyManager的OnCallStateChanged方法，用SpeechRecognizer获取语音转录。

public class MyActivity extends Activity implements TelephonyManager.OnCallStateChangedListener {

    private TelephonyManager mTelephonyManager;
    private SpeechRecognizer mSpeechRecognizer;
    private boolean mIsRecognizerRunning = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mTelephonyManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
        mTelephonyManager.listen(this, PhoneStateListener.LISTEN_CALL_STATE);

        mSpeechRecognizer = SpeechRecognizer.createSpeechRecognizer(this);
        mSpeechRecognizer.setRecognitionListener(new MyRecognitionListener());
    }

    @Override
    public void onCallStateChanged(int state, String incomingNumber) {
        switch(state) {
            case TelephonyManager.CALL_STATE_RINGING:
            case TelephonyManager.CALL_STATE_OFFHOOK:
                startRecognition();
                break;
            case TelephonyManager.CALL_STATE_IDLE:
                stopRecognition();
                break;
        }
    }

    private void startRecognition() {
        if (!mIsRecognizerRunning) {
            Intent intent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
            intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
            intent.putExtra(RecognizerIntent.EXTRA_CALLING_PACKAGE, getPackageName());
            intent.putExtra(RecognizerIntent.EXTRA_PARTIAL_RESULTS, true);
            intent.putExtra(RecognizerIntent.EXTRA_SPEECH_INPUT_MINIMUM_LENGTH_MILLIS, 2000);
            mSpeechRecognizer.startListening(intent);
            mIsRecognizerRunning = true;
        }
    }

    private void stopRecognition() {
        if (mIsRecognizerRunning) {
            mSpeechRecognizer.stopListening();
            mIsRecognizerRunning = false;
        }
    }

    private class MyRecognitionListener implements RecognitionListener {

        @Override
        public void onReadyForSpeech(Bundle params) {}

        @Override
        public void onBeginningOfSpeech() {}

        @Override
        public void onRmsChanged(float rmsdB) {}

        @Override
        public void onPartialResults(Bundle partialResults) {
            ArrayList results = partialResults.getStringArrayList(SpeechRecognizer.RESULTS_RECOGNITION);
            String recognizedSpeech = results.get(0);
            // 每次有新的partial results返回时，处理新