Human beings putting their voices together has to be one of the earliest cultural practices we have, but for many modern folk, it only happens in very specific times and places — at religious gatherings, for example, or around a birthday cake or during the seventh inning stretch of a Red Sox game. ImproVox — five Maine musicians who pursue the practice of vocal improvisation — are on a mission to bring people back to their vocal roots, and they will bring that mission to the sonorous Cider Barn of Rockport’s Carver Hill Gallery Sunday evening, Jan. 31.

Calling what ImproVox does a mission makes it sound serious, and these singers are serious about the transforming power of vocal music, but the workshops and performances they present also are a lot of fun, for the group, its workshop participants and its concert audiences.

“We’ve tried recording what we do, but it’s something like trying to capture the Northern Lights … you really have to be there to experience it,” said Deb Hensley of Belfast, one of the group’s members.

Sunday’s experience will begin at 6 p.m. with what the group calls a vocal Vortex workshop, followed at 7:30 p.m. by an a cappella performance by ImproVox and, to some degree, the audience.

“We involve the audience as much as they like,” Hensley said.

Space in the Cider Barn is limited, so Carver Hill, located at 264 Meadow St., is encouraging advance signup. Cost is $15 for both workshop and concert; space may be reserved by calling 236-0745.

Ask the members of ImproVox how the group came together and each has a different answer, said Hensley. Almost all have studied with Rhiannon, a member of Bobby McFerrin’s Voicestra. Hensley, a consultant on the value of music and art in early education who currently works from home for the Center for Ecological Living and Learning, frequently travels to attend Rhiannon’s workshops, most recently by invitation.

When Hensley and her family moved from New York to Maine, she said, she needed “to find my people” – people who love to play with their voices. She started meeting people around the state for improvisational singing, and these gatherings eventually led to her and three other singers making a commitment to work together. Almost all of them used music in their working lives — one is a full-time musician — and all have been involved with music all their lives. They came from around the state and various walks of life: Dr. Fred White is a psychologist who performs on a number of instruments and with a number of groups; Kathy Slack is a singer, actor and teacher; and Martin Swinger is a well-known Maine singer/songwriter. With the addition of vocal coach and singer Matt Loosigian, ImproVox came together.

“Everyone’s a gem, and Matt really brought us to a new level of professionalism,” said Hensley, hastening to add that the group has no director per se.

Even though they live in different parts of the state and have busy lives, the five members of ImproVox manage to meet once a week, either in Augusta or Brunswick. They do perform some prepared pieces, but the heart of the group is improvisation and while that by definition means creating music on the spot, they rehearse.

“What we’re doing is rehearsing a process, a technique,” said Hensley. “Improvisation is a tricky thing. It’s not structure-less or free form, it’s open.”

Established forms the group will work with during their weekly sessions include stacking interlocking parts — their vocal ranges approximate the standard bass/tenor/alto/soprano paradigm, although Hensley and Slack switch around — long tones, creating rounds in the moment, playing with rhythm and percussion, and working to match vocal tone.

“We’re always saying, let’s try this or hey, we haven’t tried that,” said Hensley.

That willingness to try something new and explore where it goes is key and part of the reason vocal improvisation “fires my belly up,” said Hensley.

“It pushes the edges and makes you take risks,” she said. “It requires you to say ‘yes’ over and over … I think the world needs that.”

Most of the people who come to a Vortex workshop love to sing and are looking for something new. Others used to sing but haven’t done it for a long time, often because someone told them they shouldn’t.

“One of our missions is to invite people to go back to their ‘When did you stop singing?’ moment; it’s kind of a mantra for us,” said Hensley who, with Swinger, offers workshops to teachers and students around reclaiming the power of raising one’s — and one’s community’s — voice in song.

“People always leave the workshops really lifted and just wanting to sing,” she said.

The concert that follows Sunday’s Vortex workshop will offer prepared pieces ranging from McFerrin’s arrangement of the 23rd Psalm to a reworked version of Doug Kershaw’s “The Cajun Stripper.” ImproVox has come up with its own lyrics for that saucy number, and the audience Sunday may come up with lyrics for one of the concert’s improvised works. People will be invited to fill in slips that read “I am the one who ________,” and the results will be used.

“Audience” is not quite the right word, said Hensley: “We’re looking for more a fuller tribe.”

In that spirit, Hensley said she and the other members of ImproVox would love to have more opportunities to share what they continue to find as nourishing as it is interesting.

“We all feel a real passion for bringing music to the front of culture,” she said.

And while the Cider Barn will be filled with sound Sunday night, she added, “This is a work about deep listening … it’s almost more about silence than anything else.”

For more information about ImproVox, visit improvox.com.

VillageSoup Art/Entertainment Editor Dagney Ernest can be reached at 207-594-4401 or by e-mail to dernest@villagesoup.com.