Technician & Spring Clamp Sounds
I was using Technician for the reduced repair hearing distance along with the changed addon for toolboxes, "Spring Clamp" which also says it reduces repair hearing distance.
When I wasn't using the toolbox, Technician was working as intended, making the repairing sounds quieter and presumably reducing the hearing distance along with it, but once I start repairing with the Spring Clamp Toolbox, I'm pretty sure the repairing sound was either louder than usual or just normal sounding (Normal/Louder based on regular repair - no technician equipped).
I only tested one round with Technician on so I don't even know if the addon itself is working as intended.
Edit: Tested a round using only the spring clamp toolbox without Technician. The addon alone is working as intended.