We were on Sound Walk, a programme where participants walk around Ha Noi's Old Quarter using GPS-enabled smartphones to hear the historical sounds of each destination. Walkers go at their own pace, choosing where to linger and where to speed up.
"What you hear depends on your position," explained Joshua Kopecek, the British musician who initiated the project. "If you love the sound of a street, just keep standing on it or walk slowly. The sound will loop again and again until you move to another street."
In the space of an hour, we walked from the Cathedral to Dong Xuan Market, on the northern side of the Old Quarter. On the way, we enjoyed the sound of vendors' voices and tramcars as well as traditional music such as xam (blind buskers' music) and ca tru (ceremonial music).
The sounds illuminate the streets' original purposes, some of which are still accurate.
On Hang Vai, the street of pipe-makers, participant Le Hoa heard a smoker taking a deep puff and was unsure if the source was her headphones or the man smoking a bamboo pipe in front of her.
But when she took off her headphones outside a pagoda where the boisterous sound of musical instruments and singing filled the air, indicating that a hau dong (spiritual performance to serve the gods) was taking place, she heard only tranquil silence.
"Ha Noi's the most unique city in the field of sound," said Kopecek, who has lived in the city for several years. "There are so many sounds in the city: the voice of vendors crying, music performed on streets, and vehicle noises."
Dinh Le Van, an international project co-ordinator at Viet Nam National University, and computer science specialist Mathias Rossignol joined Kopecek in the project.
The artists used historical documents and interviews with senior Hanoians and historians Duong Trung Quoc and Le Van Lan to accurately recreate the sounds of the past.
Last year, the programme drew around 100 Vietnamese and foreign participants, including blind children from Nguyen Dinh Chieu School.
"It was so meaningful when we helped the blind students discover the city through street sounds," said Van. "They told me that although they couldn't see the city, they felt it with their hearts."
Duong Bui Khanh Linh, a visually impaired student, said, "I was so happy to hear the peaceful sounds of old Ha Noi through the trains passing, the sound of the monochord, the cries of children, the sounds of glasses clinking together. When I heard the electric tram, I imagined it, but I don't know if it looks the way I imagined it."
Kopecek said this year's event would feature contemporary music in addition to the sounds of Ha Noi's Old Quarter.
"This year we are launching the project in two cities at opposite ends of the world, Copenhagen and Ha Noi, and offering two sound artists from those cities - Vietnamese composer Luong Hue Trinh and Danish sound artist Hans Sydow - a unique opportunity to create a work of art for a new medium," he said.
