The Lord Of The Rings: Gollum Is Paywalling Elven Voice Acting
The Lord of the Rings: Gollum will feature full Elvish voice acting, but only if you pick up the special edition. The Lord of the Rings: Gollum: Precious Edition will cost an extra £10, and will come bundled with some additional exclusives, including the Sindarin voice-over pack.
Anyone with the pack will be able to have the Elven characters speak their fictional language of Sindarin, presumably with English subtitles. However, this will only be available to those who purchase the Precious Edition, or buy the DLC separately after launch. This could suggest there will be very little Sindarin spoken in the base game, saving it for the DLC.