This same problem occurred in SoCal, when Metrolink started service on the former Espee Baldwin Park line. Residents there were used to one local freight a week, not 6 to 8 trains a day. Metrolink had to relocate the horns on their diesels & cab cars to appease the locals.
This problem also occurred in the Auburn, WA., area, when BNSF re-opened their line over Stampede Pass in 1995. Those who were told " Those tracks are abandoned " were surprised & angry to hear freights running at all hours of the day & night. Although the line only hosts 3 to 4 trains a day, the local residents, & City of Auburn, raised a royal fuss, taking BNSF to court. BNSF's reply was that they had never abandoned the line; they just had not used it in a while. Wah - Wah - Wah said the locals, to no avail.
Let the Buyer Beware...