Nearly two dozen Palm Beach County firefighters are suing a publicly-traded company claiming a siren it produces for emergency vehicles robbed them of their hearing. In the lawsuit filed this week in Palm Beach County Circuit Court, current and former firefighters for Palm Beach County Fire Rescue and West Palm Beach and Boca Raton fire departments say Federal Signal Corp. should have warned them of the hazards of long-term exposure to the high-intensity sirens. “Federal Signal provided no warnings or inadequate warnings to consumers and end users … about the dangerous propensities of the noise emitted by the sirens,” Pennsylvania attorney Carmen DeGisi wrote in the lawsuit. “Repeated exposure over a period of time to the noise … (has) caused permanent, irreversible hearing loss to the plaintiffs.”