Origin of the pronunciations of 観音 and 漢音


The Japanese name for the deity Guanyin, 観音, seems as far as I can tell to be
almost universally pronounced かんのん _Kannon_ , and not かんおん _Kan’on_.

The origin of the name, as
[Wikipedia](https://en.wikipedia.org/wiki/Guanyin#Etymology) correctly gives
it, is an Old or Middle Chinese translation of the Sanskrit name अवलोकितस्वर
_Avalokitásvara_ (later supplanted by अवलोकितेश्वर _Avalokitéśvara_ ) ‘he who
looks down upon sound’.

The first of the two characters used in the Chinese translation, 觀 is
pronounced _guān_ /kʷan˥/ in modern Mandarin and is usually reconstructed as
/kʷan/ or /kʷɑn/ in Middle Chinese. The Japanese pronunciation かん _kan_
(earlier くゎん _kwan_ ) follows directly from this pronunciation.

The second character, 音 ( _yīn_ /(j)in˥/ in Mandarin), is reconstructed as
something like /ʔiəm/ or /ʔjəm/ or /ʔi(ɪ)m/ in Middle Chinese. The Japanese
Go’on pronunciation, おん _on_ , follows fairly directly from this
reconstruction, representing dialects where the /ə ~ ɪ/ was rounded and
remained; while the Kan’on pronunciation, いん _in_ , represents dialects where
the initial /i ~ j/ merged with the nucleus, yielding /(j)i/. Whatever the
precise form of the vowel, it definitely had a vocalic/glide initial.

Putting these two together, thus, should yield 観{かん}音{おん} _kan’on_ , and it
does seem to, rarely. Most commonly, though, it yields 観{かん}音{のん} _kannon_ ,
as though 音 began with a nasal, which it obviously doesn’t.

Where does this extra nasal come from? Is it just simple
[連声{れんじょう}](https://ja.wikipedia.org/wiki/%E9%80%A3%E5%A3%B0) in action?

And if so, then what about the historically almost entirely identical
漢音{かんおん}? The first character there, 漢 (Mandarin _hàn_ /xan˦˩/) is
reconstructed as Middle Chinese /xan ~ xαn/ or /han ~ hɑn/, with a non-
labialised spirant rather than a labialised plosive as the initial, but with
the same final (and the initials merged in Japanese anyway). So if 連声 hits 観音,
it would be logical to expect it to also hit 漢音, or indeed 幹音{かんおん}, where the
first character is reconstructed as /kan ~ kɑn/ and thus even closer to 観. Yet
none of those seem to have gathered an extra nasal.

## How random was 連声 when it was productive? How come it affected 観音, but not
漢音, if 連声 is indeed what lies behind the extra nasal in 観音?




I can only answer part of your question: the shift from かんおん to かんのん in the
reading of 観音 is listed by several sources as due to 連声. (Shogakukan's 国語大辞典,
and [大辞林 and 大辞泉](https://kotobank.jp/word/%E8%A6%B3%E9%9F%B3-471193))

The [Japanese Wikipedia article on
観音](https://ja.wikipedia.org/wiki/%E8%A6%B3%E9%9F%B3%E8%8F%A9%E8%96%A9#.E5.90.8D.E7.A7.B0.E3.81.AE.E7.94.B1.E6.9D.A5)
states:

> 日本語の「カンノン」は「観音」の呉音読みであり、連声によって「オン」が「ノン」になったものである。

The [Japanese Wikipedia article on
連声](https://ja.wikipedia.org/wiki/%E9%80%A3%E5%A3%B0) interestingly suggests
that the 音読み of kanji could end in `/t/`, `/m/`, or `/n/`. Only `/n/` persists
in the modern language as an ending. The article also states (emphasis mine):

> 江戸時代以降になると、-t は独立の音節である「ツ」または「チ」にかわり、また -m および -n は撥音で発音されることが一般的になり、
> **漢語の連声はほとんど見られなくなったが、一部の漢語には今も痕跡的に残っている。**

The article lists a few other examples of 連声 following a first syllable ending
in ん.

As to why 連声 occurs in 観音 but not 漢音, I cannot find anything specifically
explaining why. To speculate, it might be a matter of deliberate
differentiation. There's also the way that 音 in 漢音 as `on` is specifically
about _sound_ , and matches the `on` in other kanji-reading-related words like
呉音. Meanwhile, the 音 in 観音 is only etymologically about sound -- in terms of
the modern term, `Kannon` is basically a name, and thus the _sound_ element of
音 isn't as relevant.




I can only answer part of your question: the shift from かんおん to かんのん in the
reading of 観音 is listed by several sources as due to 連声. (Shogakukan's 国語大辞典,
and [大辞林 and 大辞泉](https://kotobank.jp/word/%E8%A6%B3%E9%9F%B3-471193))

The [Japanese Wikipedia article on
観音](https://ja.wikipedia.org/wiki/%E8%A6%B3%E9%9F%B3%E8%8F%A9%E8%96%A9#.E5.90.8D.E7.A7.B0.E3.81.AE.E7.94.B1.E6.9D.A5)
states:

> 日本語の「カンノン」は「観音」の呉音読みであり、連声によって「オン」が「ノン」になったものである。

The [Japanese Wikipedia article on
連声](https://ja.wikipedia.org/wiki/%E9%80%A3%E5%A3%B0) interestingly suggests
that the 音読み of kanji could end in `/t/`, `/m/`, or `/n/`. Only `/n/` persists
in the modern language as an ending. The article also states (emphasis mine):

> 江戸時代以降になると、-t は独立の音節である「ツ」または「チ」にかわり、また -m および -n は撥音で発音されることが一般的になり、
> **漢語の連声はほとんど見られなくなったが、一部の漢語には今も痕跡的に残っている。**

The article lists a few other examples of 連声 following a first syllable ending
in ん.

As to why 連声 occurs in 観音 but not 漢音, I cannot find anything specifically
explaining why. To speculate, it might be a matter of deliberate
differentiation. There's also the way that 音 in 漢音 as `on` is specifically
about _sound_ , and matches the `on` in other kanji-reading-related words like
呉音. Meanwhile, the 音 in 観音 is only etymologically about sound -- in terms of
the modern term, `Kannon` is basically a name, and thus the _sound_ element of
音 isn't as relevant.

