Nicolas Party's giant colourful heads have landed in the Piper Gallery, and the effect is amazing. Almost everyone lets out an involuntary 'Wow' at the vibrant colour and sheer size of the five uniform but varied heads spread out across the space. Although huge (five feet high or so) they don't overwhelm the space, but stand facing in different directions so that you can't see all the heads from any one spot. Each has a hidden speaker underneath so that they seem to be muttering snippets of past Modern Art Oxford events. They're a far cry from the previous occupant, Aleksandra Mir, whose vast canvases seemed somehow very far away.

Party himself is Swiss-born but works in Brussels and New York. The Speakers project was born of his first visit to Oxford, where he was struck by the stone Emperors outside the Sheldonian and the Museum of the History of Science in Broad Street. They stood so prominently, powerful but anonymous, individual but not portraits of real people. Those of us who live in the city probably barely notice them any more, but seeing them fresh, Party found them masculine and bearded, and wanted to create a set of female heads in response.

The heads were prototyped using 3D printing and very up to date technology, and based on stylised, anonymous shop mannequin style figures. But the finishing, with wood, wire, plaster was a much more handcrafted process. They were shipped from Brussels in their white plaster form, brought into the Piper Gallery through a mysterious and secret process, and then painted in situ. Party suggests that the process of working in an unfamiliar space changes the work, as no doubt did the eager passers-by, peering through from the Hannah Ryggen exhibition next door! The journey of the heads echoes the marble statues from antiquity but in reverse - now pure white we forget they would once have been gaudily painted.

So far, so fab. The part that raises questions for me is about their femininity. For a start, the heads are quite androgynous in shape. We know they're female because the artist has told us so. There are pointers, like the sculpted eyebrows and lipstick, a downcast gaze, but also short hair and gamine faceshape. It's a good illustration of societal norms at play.

Then we have the response to an imbalance of male power, by a male artist. The literature is careful to note this is not THE response but A response to the Emperors. What we have here is Party's twopenn'orth thrown into the debate about feminism, and again it's a good starting point. Modern Art Oxford have a lot of events planned, not directly related to the Speakers but encompassing questions about feminism and suffrage (and revelling in the fact that it's about to be the centenary of the Representation of the People Act 1918, which gave women the vote, albeit those over 30). And of course with Modern Art Oxford's championing of female artists one cannot question their feminist and egalitarian credentials.

It is of course impossible to sum up women, but one thing I do think of as a widespread female trait is that of striking up conversation with strangers. Women are sociable. With their blank expressions staring out in different directions, these Speakers seem to be misnamed, and while I can see they create a more theatrical and interesting space this way, I feel sad they don't celebrate the skill of engaging with others.

But who wants art that tidily answers questions, clears up the debate over feminism, and has the last word? Sometimes it takes an outside observer to see with new eyes. If Party's gaze illuminates something about my city, or my gender, that I have overlooked then great. Party, as a classically trained graffiti artist with a distinctly Magritte-ish air is probably the sort of disruptive influence that an entrenched and age-old conversation needs.

Outsized heads stand up like bold characters and gender fluid perceptions result from the clean outlines of the features on Nicolas Party’s work. Inspired by Japanese Noh masks and Egyptian Sarcophagi the faces project a bold expression. The eyes are open and seemingly absorb the room in this exhibition of Speakers.

The former graffiti artist Nicolas Party has created a 2 hour soundscape that plays on a loop. This interactive experience verges on theatrical as the visitor is immersed in the extremes of being female. The work is a response to the masculine architecture and institutions of Oxford, particularly the Emperors’ Heads outside the Sheldonian Theatre. These stone heads on the railings are thought to be crafted in the likeness of notable pillars of society from the 17th century. Party’s approach is different. These are not real people although they magnetise a full personality from their made up faces. Perhaps these women embody the dreams and achievements of the female body.

The gallery walls are orange and the space feels welcoming. Party uses it to introduce a new way of looking at a city that has its style set in stone.

The heads on display are painted in situ in the gallery and use expressions of feminine identity e.g. hair styles and make up that the artist believes viewers use to define gender. The stone heads outside the Sheldonian Theatre look decidedly male with their beards. But then again, who knows?