As you know, this year it wasn’t possible for fans to gather at King’s Cross station on 1st September to celebrate Back To Hogwarts. To celebrate the moment remotely, Pottermore Publishing created an immersive Harry Potter audio experience especially for the occasion: Journeys to Hogwarts.

In the experience, you are transported to a bustling King’s Cross alongside Harry Potter – accompanied by rattling trolley and the flapping wings of Harry’s owl, Hedwig. The sounds around you take you into memorable moments on the Hogwarts Express during Harry’s different journeys back to school, including scenes from Harry Potter and the Philosopher’s Stone, Prisoner of Azkaban, Goblet of Fire and Order of the Phoenix.

The voices of the characters are by members of the London cast of Harry Potter and the Cursed Child. But how did the team make it sound exactly like you’re at the station and on the Hogwarts Express with Harry? That’s where the sound technicians at the post-production studio Molinare come in.

The team at Molinare used the latest acoustic techniques to create the immersive soundscape, including taking a binaural microphone to King’s Cross station itself to record ambient noises.

The team donned face masks and kept their distance at the station to record in a Covid-secure way. Molinare’s Creative Director, Glen Gathard, explains further: ‘We recorded all of our atmosphere beds from scratch with our Neumann KU100 microphone, or as we call him ‘Barry Binaural’ [a dummy human head with microphones in the ear positions]. Barry and our amazing recordists Alex and Guy visited King’s Cross, roamed the streets of London for voices and even took foley props on to the platforms of the station and performed the sound around the Dummy head, with our Foley Artist, Zoe Freed, to give a truly immersive binaural listening experience with correct positioning in your listening field.’

In case you need reminding, ‘Foley’ is the reproduction of sounds created in a studio and mixed into the audio afterwards. For example, replicating the rattle of a trolley excitedly rushing towards a wall. Barry has a history in the Wizarding World – he was used to capture the footnotes in the Fantastic Beasts and Where To Find Them audiobook, narrated by Eddie Redmayne.

But what exactly is binaural sound? ‘Binaural recording is a method of recording sound that uses two microphones, arranged with the intent to create a 3D stereo sound sensation for the listener,’ explains Glen. ‘When the recorded audio signal is reproduced through any headphones the listener perceives a sound image almost identical to the one that they would have heard at the recording location of the dummy head (this is known as ‘head-related stereophony’). When played back through loudspeakers, the sound matches to a high degree that of conventional stereo microphones, placed in the same position. However, a superior quality is added – that of a distinct spatial depth perception. Barry was positioned at different points of the station and at times on the back of our recordists to create the sense of the motion of walking or running in the station. Not only was this an excellent method to capture these sounds it was also really amusing to watch our team carrying a grey bald head on their shoulders in public!’

Aside from this strange sight, the team went back to some favourite techniques and innovated some new ones when doing the rest of the sound design. The Dementors were recreated using props that were used on the Harry Potter films (some of Glen’s team worked on those and the two Fantastic Beasts films), with the voices of family and loved ones in the team’s creative bubbles mixed in.

Sound designer Alex Gibson frequently breathed and whispered into Barry’s ears to create new sounds, and Glen credits him for creating the depth and detail of the Hogwarts Express soundscape. Alex even recorded his cats at home for the cats populating Platform Nine and Three-Quarters. According to Glen, he wasn’t the only one who was pleased with his work: ‘One of our sound recordists, Francesca, is particularly proud of her scream in the Dementors section. She was extremely proud to be part of the soundscape.’

When it came to mixing it all together, the process was extremely detailed and the team took inspiration from their work with video games to get the richness of the soundscape exactly how they wanted it. They changed direction a few times following feedback from members of the sound team, some of whom weren’t actively on the project, for an outside perspective. Glen and his team saw the project as ‘an opportunity of true escapism and an experience of wonderment and something that is very sonically different to anything you would have heard before.’

It was hard work under a tight deadline, but Glen makes it sound like it was a lot of fun for everyone making it. Ultimately, he had the most fun seeing everyone’s reactions to it: ‘…watching the amazing positive feedback from the fans on social channels about the great performances and the immersion. The world is a tricky place right now and the fact so many people got to enjoy this and for free is a great gift from Pottermore Publishing. So, by far the most fun was listening to the voices of the fans.’

Are you one of those fans? You can listen to Journeys to Hogwarts for free here. It is also available for free on a variety of platforms until 30th September. Stream on Audible via Wizarding World landing pages or in Audible Stories, look for the Harry Potter feed on Spotify, or find it on Storytel and Nextory. You can even ask: ‘Alexa, take me to Hogwarts’.