With an average life span of seven to 11 days, Blues Traveler’s John Popper’s harmonicas don’t seem to stand a chance.

And, after being exposed to other elements, some don’t even last that long.

“I can burn one out in one gig,” Popper said in a recent press release.

It gets worse. Sometimes running out of breath, Popper has even vomited into his harmonica.

“The thing you’ve gotta do then is just suck it up, chunks and all, and keep on playing,” Popper said.

No matter, the ravenous spirit of Popper’s harmonica keeps Blues Traveler’s fan base increasing in numbers.

The soul and sheer energy Popper puts through this instrument has helped Blues Traveler evolve from a “live” band to one too popular to be ignored by the music industry.

Endlessly touring, Blues Traveler will stop in Ames while promoting its sixth album, “Straight On ‘Till Morning.”

“Over the past seven years Blues Traveler has proved to be one of the prime movers in keeping the spirit of the Grateful Dead alive,” said an article in the Los Angeles Times.

“The incisive, passionate sound it’s cultivated through the years of diligent touring really shines on the group’s latest effort.”

The quartet, consisting of harmonica player John Popper, guitarist Chan Kinchla, drummer Brendan Hill and bassist Bob Sheehan, was able to spend less time on the road and more time recording this album.

“The only pressure we felt in making this record was to continue an honest dialogue with our audience,” Popper said.

“We wanted to be completely free and completely honest. I think that we pulled it off, and I hope it comes across that way to our fans.”

With influences such as J. Geils, Foghat and Z.Z. Top, Blues Traveler has fashioned and refashioned a genre of blues that can only be accredited to them.

Rolling Stone described “Straight On Till Morning” as a restoration of the balance between “aggressive interplay and melodic craft.”

“We’ve always been conscious that the live vehicle is a totally different mode of expression from capturing a performance in the studio,” guitarist Chan Kinchla said in a press release.

“We’ve always loved doing both. But the ability to really make things work in a vacuum, like you have to do when recording, is something we worked very hard at,” he added.

Playing together since high school, the band averages more than 250 shows a year playing clubs, street fairs, benefits and nitrous parties.

Blues Traveler relies on word-of-mouth by the fans in promoting itself (the band has not always been commercially popular).

So far, this means of self-promotion has worked.

Sometimes performing for an audiences of 10, Blues Traveler can return to the same place to perform for an audience of hundreds, according to a press release.

An audience of hundreds will be filling Stephens Auditorium Sunday night at 7:30 p.m. as Blues Traveler returns to Ames for the second time in three years.

Tickets are still available through Ticketmaster for $24.