Members of the public are being asked to take part in a university project that is going to be a real humdinger.
A University of Aberdeen lecturer is looking for people to help him - but it is not their time, expertise or even their money that is being sought.
Dr Suk-Jun Kim wants them to volunteer their hums, as part of a community music project. He is hoping to collect hundreds of hummed tunes, with each one representing a childhood memory of the individual contributor.
Each gathered hum will then become part of a public sound installation in the city later this month.
Dr Kim, a lecturer in electroacoustic music and sound art, said: "Humming is a personal, intimate act. Usually when people hum, it is either to themselves or perhaps to a loved one, maybe to soothe a child. Offering hums to others means that you are inviting others to enter your personal space.
"This project is designed to examine the relations between people and places, and how a person's memory plays a role in this."
Participants will be asked to hum a tune that reminds them of their early years.
It is hoped that anyone attending the installation who hears the hum of a tune that they remember from their childhood will then feel a connection to the original hummer.
A large number of hums were already collected from members of the public during the summer using a "humming booth" at the city's Belmont Street gallery, Seventeen.
But Dr Kim is now collecting more hums in person with the help of a group of music students from the university.
The university said there is still time for people to volunteer their hums to the project by contacting Dr Kim directly.
The lecturer, who has already carried out the project in Berlin and New Mexico, said he is looking forward to seeing how people connect with the exhibit.
"It would be great to have as many people's hums included in the composition as possible, so don't hesitate to come along and get involved," Dr Kim said.
He can be contacted by emailing email@example.com.
The exhibit, supported by the sound festival and Aberdeen City Council, will be open to the public from November 14-30.