colorado71 - That is behaviour programmed in by the locomotive creator and does not affect all locos.
Here's one where the bell always sounds when you blast the horn: <kuid2:45324:100248:2> CSX C40-8W yn3 (ex-CR) (I use the 'B' key to turn it off when I don't want to hear the bell sounds).
The majority of built-in locos do NOT have simultaneous bell sounds, especially non-US locos of course.
Here's an example of a built-in US loco that does NOT sound the bell when the horn is blown: <kuid2:45324:100141:8> SP SD40T-2 - (There are many others).
Here's one where the bell always sounds when you blast the horn: <kuid2:45324:100248:2> CSX C40-8W yn3 (ex-CR) (I use the 'B' key to turn it off when I don't want to hear the bell sounds).
The majority of built-in locos do NOT have simultaneous bell sounds, especially non-US locos of course.
Here's an example of a built-in US loco that does NOT sound the bell when the horn is blown: <kuid2:45324:100141:8> SP SD40T-2 - (There are many others).