Tests on animals, published in the Journal of Investigative Dermatology, showed healing times could be cut by nearly a third.
Experts said the early results were "quite impressive" but needed to be tested on people.
More than 200,000 people in the UK have chronic wounds which can take weeks to heal.
Ultrasound is already used to heal some bone injuries.
A team from the Universities of Sheffield and Bristol tried the technology on mice with chronic wounds, which do not close readily and often become infected.
Pressure sores from lying or sitting in the same position for too long, and diabetic foot ulcers which can lead to amputation, are both types of chronic wound.
They become more common when we age due to a decline in our body's ability to repair itself.
The high frequency sound waves physically vibrate cells in and around the wound. The process effectively wakes up the cells to make them more responsive to the wound.
The study showed that in both old and diabetic mice, healing times were reduced from nine to six days.
The report said ultrasound was "restoring healing rates to those observed in young healthy animals".
In the tests the team were treating the wounds before they become chronic, so they will need to test the power of ultrasound on wounds that have been there for weeks.
Dr Mark Bass, one of the researchers from Sheffield University, told the BBC News website: "At the moment, treatment is based around stopping the infection and hoping it heals, with ultrasound we are promoting the healing of the wound."
"It's activating the normal healing process, that's why it's an attractive therapy; the ultrasound is simply waking up cells to do what they do normally."
The researchers now need to study the approach in people, which they expect to do in the next year.
"We're looking at 200,000 patients currently with a chronic wound, all those may well benefit from the technology," Dr Bass said.
The researchers are using broadly the same equipment that is used in an ultrasound scan during pregnancy.
Dr John Connelly, from Queen Mary, University of London, said: "They're getting almost complete reversal of impaired wound healing which is quite impressive."
So does it have potential as a treatment?
"I think it could, but that's a major question as wound healing is quite different between humans and mice," he said.
"One of the big wound-healing treatments is negative pressure - putting the wound under a vacuum - that acts through mechanical stimulation, so it's entirely reasonable that ultrasound may also work."
A blast of ultrasound can help stubborn chronic wounds heal more quickly, a study suggests.