Azure speech to text with numbers

Question

A use case for my app is to convert speech (single word utterances) to text. I need to use Azure speech to text for this. Sometimes the speech needs to be converted into an integer - I need to submit the response as a quantity for example. My question is is there anyway, via the REST API, to tell the speech to text service I want a numeric result? Currently it is returning things like 'one' instead of '1' and 'free' instead of '3'. I don't think there is a way to do this from the documentation but I wanted to see if anyone else has solved this problem before I think of a way around it. This is the code I am using in my proof of concept project:

 public static async Task SpeechToTextAsync(MemoryStream data, ISpeechResultCallback callBack)
    {
        string accessToken = await Authentication.GetAccessToken();

        IToast toastWrapper = DependencyService.Get<IToast>();

        if (accessToken != null)
        {
            toastWrapper.Show("Acquired token");
            callBack.SpeechReturned("Acquired token");
            using (var client = new HttpClient())
            {
                HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create("https://westus.stt.speech.microsoft.com/speech/recognition/conversation/cognitiveservices/v1?language=en-GB&format=detailed");

                request.SendChunked = true;
                request.Accept = @"application/json;text/xml";
                request.Method = "POST";
                request.ProtocolVersion = HttpVersion.Version11;
                request.Host = "westus.stt.speech.microsoft.com";
                request.ContentType = @"audio/wav; codecs=audio/pcm; samplerate=16000";
                // request.Headers["Ocp-Apim-Subscription-Key"] = Program.SubscriptionKey;
                request.Headers.Add("Authorization", "Bearer " + accessToken);
                request.AllowWriteStreamBuffering = false;

                data.Position = 0;
                byte[] buffer = null;
                int bytesRead = 0;
                using (Stream requestStream = request.GetRequestStream())
                {

                    buffer = new Byte[checked((uint)Math.Min(1024, (int)data.Length))];
                    while ((bytesRead = data.Read(buffer, 0, buffer.Length)) != 0)
                    {
                        requestStream.Write(buffer, 0, bytesRead);
                    }

                    // Flush
                    requestStream.Flush();
                }

                try
                {
                    string responseData = null;
                    using (WebResponse response = request.GetResponse())
                    {
                        var encoding = Encoding.GetEncoding(((HttpWebResponse)response).CharacterSet);

                        using (var responseStream = response.GetResponseStream())
                        {
                            using (var reader = new StreamReader(responseStream, encoding))
                            {
                                responseData = reader.ReadToEnd();

                                AzureSTTResults deserializedProduct = JsonConvert.DeserializeObject<AzureSTTResults>(responseData);

                                if(deserializedProduct == null || deserializedProduct.NBest == null || deserializedProduct.NBest.Length == 0)
                                {
                                    toastWrapper.Show("No results");
                                    callBack.SpeechReturned("No results");
                                }
                                else
                                {
                                    toastWrapper.Show(deserializedProduct.NBest[0].ITN);
                                    callBack.SpeechReturned(deserializedProduct.NBest[0].ITN);
                                }
                            }
                        }
                    }
                }
                catch (Exception ex)
                {
                    toastWrapper.Show(ex.Message);
                    callBack.SpeechReturned(ex.Message);
                }

            }
        }
        else
        {
            toastWrapper.Show("No token required");
            callBack.SpeechReturned("No token required");
        }
    }

And here is an example of the result that I would like to be '1':

{
 "RecognitionStatus": "Success",
  "Offset": 0,
  "Duration": 22200000,
  "NBest": [
    {
      "Confidence": 0.43084684014320374,
      "Lexical": "one",
      "ITN": "One",
      "MaskedITN": "One",
      "Display": "One."
    }
  ]
}

Answer 1

I suggest to use this nuget from Microsoft. It works like a charm, here an example.

NumberRecognizer.RecognizeNumber("I have two apples", Culture.English)

Answer 2

According to the offical document Speech-to-text REST API , there is no option can help converting the numberic words to numbers.

Considering for the numberic words in English have the pattern in syntax, you can use a simple algorithm to implement the feature for converting words to numbers. As references, you can follow these below to write your own one in C# by yourself.

1. Converting words to numbers in c++
2. Translate (Convert) Words to Numbers RRS feed in SQL Server
3. Words in Numbers

Hope it helps.