CLEARWATER — Five current and former Clearwater firefighters are suing a siren manufacturer, claiming that some of the Illinois-based company's sirens were so loud they caused hearing loss.

Pat Scanlon, 64, who retired from Clearwater Fire & Rescue in 2008, says that when he goes to sleep at night, it sounds like a jet is firing up next to him.

"And when I wake up, it's still there," he said Tuesday. "It's constant."

The lawsuit joins others across the country brought forth by thousands of firefighters against Federal Signal Corp. Many of the lawsuits are connected to the same Pennsylvania-based law firm.

The lawsuit says the sirens were "inherently dangerous, defective and hazardous" and that the company should have tested the sirens' effects and warned users that prolonged exposure to the noise would be harmful to human hearing. It seeks $75,000 for each firefighter, among other damages.

"As a result of the injuries sustained," the lawsuit says, "they have suffered a permanent decrease of their hearing and thereby have suffered a diminution in their ability to enjoy life and life's pleasures."

David Duffy, an attorney for Federal Signal, said in a statement the company "has strong defenses to these cases and has prevailed in a string of jury trials."

"Sirens are vital public safety products and save lives," he said. "Federal Signal is committed to defending its quality siren products and will litigate these cases as necessary."

The law firm, Bern Cappelli LLP, declined to comment. Steven F. Smith and Gregory M. Newland, two of the firefighters, declined to comment. The other two firefighters — Wade Bishop and Mark Herny — could not be reached for comment.

But Scanlon provided some insight as to how he became involved in the suit.

When he started at the department in 1980, many fire trucks didn't have air conditioning, so firefighters would ride around with the windows down or in open-air seats. The sirens blared with no insulation, he said.

Within the last five years before his retirement, Scanlon said he noticed his hearing deteriorating. He started experiencing the ringing in his ears known as tinnitus. A doctor told him there was nothing he could do. At a Florida Professional Firefighters conference five or six years ago, he met lawyers who told him about the siren lawsuit.

"And I looked at it and said, 'Wow, let me look into this,'" he said.

Now, he attributes much of his hearing loss to the earlier years of his career, he said.

"It's progressively getting worse. Of course, I'm getting older also," he said. But "I've been around sirens for 28 years. This is an occupational hazard."

Thousands of firefighters have felt the same way. As of December 2015, about 4,400 current and former firefighters had sued the company, according the Associated Press. That number has since grown. Recent news reports show 23 firefighters from Palm Beach County, Boca Raton and West Palm Beach sued the company.

Clearwater Fire & Rescue is not a party in the case. When asked about the department's history with the siren brand and whether officials had received complaints about the sirens, spokesman Rob Shaw declined to comment.

Sean Becker, president of the Clearwater Fire Fighters Association, said he hasn't received complaints about the sirens since he became president in January 2015. He didn't know much about the litigation but said he believed it has more to do with the period Scanlon referred to when fire trucks had open cabs, no air conditioning and no hearing protection.

Firefighters now wear headsets in the trucks to listen to the radio and communicate with each other.

"Ultimately, there are much better standards today," he said.

Scanlon agreed that conditions had gotten better toward the end of his career.

"But I believe the damage was already done by that time," he said.

Senior staff researcher Caryn Baird contributed to this report. Contact Kathryn Varn at (727) 893-8913 or kvarn@tampabay.com. Follow @kathrynvarn.