Update README.md

README.md

@@ -13,4 +13,53 @@ tags:
 pretty_name: Cantone
 size_categories:
 - 10K<n<100K
----
+---
+
+# Cantone
+
+A dataset of 34,489 recordings of Cantonese syllables by 10 speakers.
+Those syllables are generated through the Cantonese speech synthesis engines of Amazon, Apple, Google, and Microsoft.
+
+All recordings are stored as WAV files with the following format
+  * Channel: mono
+  * Sample rate: 16 kHz
+  * Bits per sample: 16
+
+Here's a breakdown of the number of recordings under each speaker:
+| Company | Speaker | # Syllables |
+| --------|-------- | -------- |
+| Amazon  | Hiujin  | 3,885 |
+| Apple   | Aasing  | 2,977 |
+| Apple   | Sinji   | 2,977 |
+| Google  | A       | 3,653 |
+| Google  | B       | 3,653 |
+| Google  | C       | 3,653 |
+| Google  | D       | 3,653 |
+| Microsoft | Hiugaai | 3,349 |
+| Microsoft | Hiumaan | 3,349 |
+| Microsoft | Wanlung | 3,349 |
+
+## Dataset Construction
+
+1. Gathering
+We first identified 3,904 common Cantonese syllables based on words.hk's syllable recordings.
+The, we ask the speech synthesis APIs to pronounce each of the syllables.
+The queries use SSML's phoneme attribute to precisely specify the syllable we want. Here's a sample SSML query that fetches the syllable jyut6:
+```xml
+<speak><phoneme alphabet='jyutping' ph='jyut6'></phoneme></speak>
+```
+
+Apple voices are gathered using jyutping text directly and a native Cantonese ASR system is used to filter out unsupported syllables.
+
+2. Preprocessing
+* All audios are converted to 16kHz WAV files
+* Peak normalize all audios to -20 dBFS
+* Clip silence at the beginning and end (sound below -50 dBFS are deemed silence)
+
+3. Verification
+Occassionally, some syllables are not synthesized correctly.
+* Apple voices usually renders tone 5 syllables as tone 2: we remove all tone 5 syllables from apple voices 
+* Microsoft voices prepends consonants like ng, g, and b in front of isolate vowel syllables like aa: we remove all vowel syllables from microsoft voices
+
+## License
+MIT