Android TTS speaks 0 as "oh"

Question

When using Android TextToSpeech to speak messages that have digits, Android is speaking 0 (zero) as "oh" rather than "zero". All other digits are spoken as expected.

I've tried a couple different ways to speak, all of them result in this issue. First, I tried in the normal way:

    mTTS = new TextToSpeech(mContext, this);
    String text= "this is a test";
    String digits=  "0 0 0 1";
    String finalString= text+digits;

    // speak something using google TTS
    Bundle lParams = new Bundle();
    lParams.putInt(TextToSpeech.Engine.KEY_PARAM_STREAM, Constants.TTS_AUDIO_STREAM);
    mTTS.speak(finalString, TextToSpeech.QUEUE_FLUSH, lParams, "");

I also tried digits as "0001" (no spaces). Both ended up spoken as "this is a test oh oh oh one". Next, I tried using TtsSpans:

    mTTS = new TextToSpeech(mContext, this);
    String text= "this is a test";
    String digits=  "0 0 0 1";
    String finalString= text+digits;
    Spannable lSpannedMsg = new SpannableString( finalString );
    TtsSpan lSpan = new TtsSpan.DigitsBuilder(digits).build();
    TtsSpan lSpanText = new TtsSpan.TextBuilder(text).build();

    lSpannedMsg.setSpan(lSpan, finalString.indexOf(digits), finalString.indexOf(digits) + digits.length(),Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
    lSpannedMsg.setSpan(lSpanText, finalString.indexOf(text), finalString.indexOf(text) + text.length(),Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

    // speak something using google TTS
    Bundle lParams = new Bundle();
    lParams.putInt(TextToSpeech.Engine.KEY_PARAM_STREAM, Constants.TTS_AUDIO_STREAM);
    mTTS.speak(lSpannedMsg, TextToSpeech.QUEUE_FLUSH, lParams, "");

Even with the spanned string, the engine still spoke "this is a test oh oh oh one". Is there any way to force Google to speak 0 as "zero"? I would like to avoid investigating the string sent in and replacing 0 with "zero" as this would cause issues with other languages.

Answer 1

holder.mEmployeeId.setText("100001");
String buildNumber = holder.mEmployeeId.getText().toString();
StringBuilder builderForEmployeeNo = new StringBuilder();
for (char ch : buildNumber.toCharArray()){
    builderForEmployeeNo.append(ch);
    builderForEmployeeNo.append(",");
}
holder.mEmployeeId.setContentDescription(builderForEmployeeNo);

By using this method no matter your default locale it will read 0 as zero only