Onyomi Reading Analysis

I conducted a quick analysis of Kanji Onyomi readings.  First I wanted to know was how many unique sounds or readings there are and how frequently they occur.

	9056 Kanji in the WWWJDIC Kanji Dictionary	2500 Most Frequent Kanji in the Asahi Newspaper
1 or more Kanji	421	348
2+ Kanji	328	273
5+ Kanji	266	181
10+ Kanji	208	112

According to my results there are 421 unique Kanji Onyomi readings.  If you narrow down the 9056 Kanji that are listed in the WWJDIC Kanji Dictionary file to the 2500 most frequently printed Kanji in the Asahi Newspaper the number drops to 348.  Furthermore, if you focus on the readings for which there are 5 or more Kanji that use that Onyomi reading the number drops to 181.

What I've realized in my studies is that it is sometimes difficult to learn a new reading.  That is to say that until you've learned one or more Kanji that use a particular reading it can be difficult to learn.  I think that this is again related to the theory of association value.  The more characters you know with a particular reading the easier it becomes to learn a new character with the same reading.

Next I wanted to know which readings appear most frequently.  Here are the top Onyomi readings by frequency.

9056 Kanji in the WWWJDIC Kanji Dictionary		2500 Most Frequent Kanji in the Asahi Newspaper
Onyomi	Frequency	Onyomi	Frequency
コウ	292	コウ	106
ショウ	236	ショウ	97
ソウ	175	シ	70
シ	165	ソウ	64
カン	163	トウ	58
トウ	162	キ	57
キ	148	カン	55
セン	147	キョウ	55
キョウ	137	チョウ	48
ケン	122	カ	47

The tables are pretty similar.  Readings that are common in the large set of Kanji are also common in the most frequently used newspaper Kanji.  It's interesting to note that the readings for the 4 most frequent readings kou, shou, so, sou, all sound very similar to an English speaker.  I think this is just one of the many reasons why it takes Westerners a long time to master listening skills.  It must take hundreds and possibly thousands of hours of listening to develop deep Japanese listening ability.