have replaced the files:
OELD_jquery.js
OELD_script.js
in the distribution found here: Index of /尚未整理/共享2020.5.11/qwjs/18_OLEDonline/
with the files from here: [已结束测试]OELD Online 1.51 修正+离线发音 - #41，来自 mdictfan
now offline pronounciation works well.
have replaced the files:
OELD_jquery.js
OELD_script.js
in the distribution found here: Index of /尚未整理/共享2020.5.11/qwjs/18_OLEDonline/
with the files from here: [已结束测试]OELD Online 1.51 修正+离线发音 - #41，来自 mdictfan
now offline pronounciation works well.