Can I expect only these phonetic characters or more?

Children’s Speech Recognition Challenge
1

I collected phonetic letters from main and extra datasets and used scoring script to check if they are valid (they are valid).
That’s what I found:

phonetic_chars count
297923
i 111898
n 91048
ɑ 77628
ə 74327
t 71591
d 70436
ɪ 66453
s 59844
ɹ 53693
ɛ 49516
w 49466
k 47502
æ 46985
ʌ 45928
ʊ 40687
b 38208
ɚ 36146
l 35914
m 34477
u 33463
o 33289
ð 31564
e 31039
h 30903
f 29044
p 27322
g 25821
ː 24677
z 24175
j 18394
ɔ 15661
ŋ 12252
v 10185
θ 9506
ʃ 9022
ʧ 8903
ɫ 8134
ɾ 6571
ʤ 6301
ʔ 5670
ɐ 2174
ʝ 436
ʁ 179
c 176
ʒ 161
x 154
ɬ 117
ç 104
ɟ 100
χ 17
r 2

  • Can I expect only these characters, or should I expect more? If I need to expect another character, what kind of character should it be? Or maybe I need to remove or replace some of them.

    I understand that the distribution may vary, but I need to know what kinds of characters I should expect. This is very important for everyone, I think. It’s about the format we should expect for the future.

Please, LIKE IT if it’s useful post.

2

Only valid IPA characters as specified in the scoring script will be found in either the phonetic training or test set.

3

In phonetic track, are we supposed to predict the exact phonemes? For example, a child has a speech impediment and says “Wabbit” (/wæbɪt/) instead of “Rabbit” (/ɹæbɪt/). We predict “Rabbit”(/ɹæbɪt/) here, right?

4

@oknaitik Your task is to predict the former, /wæbɪt/, i.e. the actual speech sounds or phones, not the phonemes.

From the problem description:

The ground truth labels for the Phonetic Track are normalized phonetic transcriptions of individual utterances using the International Phonetic Alphabet (IPA), with a one-to-one mapping between Unicode characters and phones. Each transcription captures the full sequence of speech sounds in the corresponding audio clip and may include substitutions, omissions, or non-standard productions that are typically ignored in word-level ASR.