The IWG RD-ASEP Subgroup on UN R138 and UN R51 held 13 meetings between October 2024 and September 2025 to amend both regulations regarding sound emissions of electric vehicles. On UN R51, the group agreed to introduce electric vehicles into Annex 7 (ASEP) scope and to add optional sounds and SPL limit lines for M₁ and N₁ vehicles based on vehicle speed, using OICA proposal GRBP/2025/29 as basis. On UN R138, the group aimed to clarify existing text, remove grey zones, and ensure adequate safety levels while limiting environmental impact through maximum SPLs. Working documents are planned for submission to GRBP in February 2026.