It might help, but you couldn't eliminate some kind of audio indication because of those that can't see.
Platform speakers playing the train arrival noise. They can be used instead. With a few speakers pointing up/down platform, they are all near people, so they don't have to sound as loudly as a train's horn to sound as loud to the human, and this disturbs neighborhoods less, and confuses distant platforms less (e.g. Union).
By having Accessible Platform Alerts (amber ribbon & platform speakers), I propose Transport Canada shall waives the train of requiring to sound the horn. This will be very important when horns sound every 3-5 minutes (15-min trains on several routes 2-way passing each other) very close to residential areas almost 24/7 (except for a small 4 hour window).
i.e.
Proposal to Transport Canada to waive Train Horn Use at Platforms
cc: AODA (Accessibility for Ontarians with Disabilities Act)
This ATADAS proposal improves accessibility for train use by both the blind and the deaf.
If a Platform has Accessible Train Arrival/Departure Alerts System (ATADAS)
(A) Loudspeakers on platform, focussed up/down platform, playing the trainhorn sound for the specific track;
AND
(B) Bright amber-yellow light ribbon along both sides of track (see Figure 1), FLASHING twenty seconds prior to train end entering platform, ON when train stops, FLASHING ten seconds before train departure, OFF when train end fully exits platform.
Then train driver MAY
(A) avoid sounding the train horn at said ATADAS-enabled train station; to be more neighborhood-friendly, disturbing nearby residents less. It also provides better platform-localization clarity at large stations such as Union. The reasoning is that a series of loudspeakers along a platform can be just as loud as a train horn on the platform, while producing far less noise outside the platform (i.e. neighborhood, distant platforms). It is permitted that the sounding speakers be built into a waterproof amber ribbon, for easier integrated deployment at existing stations.
By AODA reasons, all train and subway stations upgraded to Positive Train Control, shall implement the Accessible Train arrival/departure alert system (AODA amendment); the reasoning is Positive Train Control signalling systems provide a way to easily signal the Accessible Train Arrival/Departure Alert System (ATADAS).
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(Sometime this year, I may email/tweet/FedEx something more substantial and prepared to Transport Canada & AODA. Even FedEx, printed on glossy paper on my photo printer to try to catch attention higher than an email message, on this regards. Longshot I know, but -- let's see. Knowledgeable volunteers welcome, PM me)