Are there standards for simultaneous interpretation equipment?
Yes and they are rather detailed.

Standards are important for language translation and interpretation services.
ISO 2603 “Simultaneous interpreting – Permanent booths – Requirements” covers the built-in installations, and ISO 4043 “Simultaneous interpreting – Mobile booths – Requirements” covers portable equipment.
There are other guidelines and standards by other bodies, such as ISO/FDIS 20109 “Simultaneous interpreting — Equipment – Requirements” or ASTM F2089: Standard Guide for Language Interpreting Services.
If you are interested in this topic, see the Further Reading section at the bottom of this page.