.java

    public void onAudioMuteClicked(View view) {
        ImageView btn = (ImageView) view;
        if (btn.isSelected()) {
            btn.setSelected(false);
            btn.setImageResource(R.drawable.audio_toggle_btn);
        } else {
            btn.setSelected(true);
            btn.setImageResource(R.drawable.audio_toggle_active_btn);
        }

        mRtcEngine.muteLocalAudioStream(btn.isSelected());
    }