Please be advised that if you use the connect app, it doesn't always correctly parse links to lemmy posts. If they're not working for you, you can follow the whole plotline on my site. (These comics are in reverse chronological order, so start at the end and work backwards.)
Well, that's for the noise where they're making the high pitch "neigh" rather than the sound this horse is making (which is the more snorting-exhaling sound)
In 5e, Paladin's steeds can only speak languages that the animal itself could speak (which for a horse, is "nothing") - they understand all the languages the paladin speaks, and can empathically communicate, but they can't speak.