Sound Experiments
===

###### 2020-02-10

The Driver Interface Units (DIUs) and Passenger Interface Units (PIUs)
on the buses need to be audible to drivers and passengers when accepting
or rejecting passes.

This document collects some data about the ambient noise, the sound level
of the legacy system and experiments with the replacement system.

| System Type | Typical dB | Button dB | Accept dB | Reject dB |
|-------------|------------|-----------|-----------|-----------|
| Ambient on Bus | 70-80      |           |           |           |
| Legacy System | 95       | 97        | 95        | 95        |
| v Acorn Squash | 80      | 74        | 82        | 82        |
| v Alfalfa Sprout | 85    | 89        | 90        | 80        |
