English passages in the same voice, too... YES24 revamps AI narration for e-books

[Financial News] Users can now listen to language-learning materials that mix Korean explanations with English example sentences in a single voice on the YES24 e-book app.
YES24 said on the 9th that it had added an “Automatic Korean-English Switching” feature to its artificial intelligence (AI)-based text-to-speech (TTS) service. The feature was included in an update for the iPhone and iPad apps on the 28th of last month.
Previously, Korean and English were read in different voices. The new feature reads continuously in the same voice, from English words within Korean sentences to quoted passages made up entirely of English. Using SELVAS AI’s “SELVAS Deep TTS On-Device” technology, it synthesizes speech directly on users’ devices, such as smartphones and tablets.
To use the feature, open a book in the app, tap “Listen” and download the AI voice, then turn on “Automatic Korean-English Switching” in the listening settings. TTS availability for each book is listed under “Usage Information” on its product page. To listen to a PDF e-book in the mobile app, the file must contain recognizable text.
YES24 introduced its AI TTS service in August last year. Playback speed can be adjusted from 0.5x to 2x. The service also supports voice-pitch settings and a timer that stops playback after a set amount of time or at a specified page.
Around 4,000 members took part in an AI voice preference poll held from August 26 to September 25. Based on the results, YES24 added two voices. Users can now choose from eight AI voices in the app.
According to YES24, per-person spending on audiobooks from January 1 through October 30 this year rose 69.3% from the same period last year. In October alone, it was up 493.6% from the same month last year.
By age group, people in their 40s accounted for the largest share of purchases (30.9%), followed by those in their 30s (24.1%) and 50s (21.9%). By genre, fiction ranked first (31.5%), followed by humanities and history (17.5%), and poetry and essays (8.6%).
Through the 26th of this month, YES24 is running a quiz in which participants listen to a passage read in English by AI and guess the book’s title. The event page features AI narration samples from English-language originals, including Andy Weir’s “Project Hail Mary.”
The 2,000-won YES gift certificate given to every participant can be used on the day it is issued to buy e-books worth at least 10,000 won, excluding payback products. Gift certificates not used that day can be reissued during the event period.
Lee Jin-gu, head of YES24’s Digital Business Division, said he expected the range of uses for e-books, including language learning, to expand further, and that the company would continue developing dedicated AI voices.

[email protected] Jang In-seo Reporter