Bittersweet symphony: using sound to influence taste

Whether its speedy drum beats on a fast food restaurant radio encouraging us to eat quicker or the sizzle of bacon frying in a pan making us salivate, sound is an integral part of the multisensory food experience – but could specific noises have an even larger part to play in the industry?

Charles Spence, head of the Crossmodal Research Laboratory at Oxford University’s Department of Experimental Psychology, was the keynote speaker at ‘Tech Food Reality’, part of this year’s London Food Tech Week. Spence is a renowned expert in the field of multisensory engagement, and as he puts it, “There’s nothing more multisensory than food.”

When it comes to food, smell and taste  are the senses that get the spotlight, but Spence argues that sounds, and what he calls ‘sonic seasoning’, play an equally integral role – one that can be taken advantage of and manipulated to provide unique culinary and dining experiences, and influence the flavours we experience.

Implementing sonic seasoning

It was one of Spence’s earlier works, ‘The Role of Auditory Cues in Modulating the Perceived Crispness and Staleness of Potato Chips’ – establishing that stale crisps are seen to be fresher when the correct ‘crunch’ sound is played – that first looked at the relationship between sounds and food. Since then, Spence has worked with restaurants and chefs the world over to develop unique sensory experiences, all backed up by science and theory.

London Restaurant House of Wolf served a ‘sonic cake pop’ for one month as part of its menu. When tucking into the dessert, guests were asked to call one of two numbers depending on which taste they wanted to amplify – the sweet number would play a high pitched noise, whereas the bitter number would play a deeper sound. “We have here a food that is itself both bitter and sweet,” says Spence. “We can’t turn water into wine with technology, but we can take a bittersweet chocolate lolly and enhance certain flavours with sounds.”

According to Spence, the ‘sweet-sound’ application is currently being looked into by restaurateurs and chefs as a means to cut sugar content in their meals, making them healthier yet still palatable for those with a sweeter tooth.

Background noise can quite dramatically affect our sense of taste too. Tomato juice makes up 27% of all drinks ordered on aeroplanes, and yet is drunk rather minimally on the ground. According to Spence’s research, people crave the savoury beverage because of how loud travelling by air can be. Aeroplanes typically have around 80-85 decibels of background noise, and this long, deep drone interferes with passengers’ ability to taste sweetness, meaning they’re more likely to opt for salty snacks on-board than chocolate bars and sweets.

Interfering with the dining experience

One of the biggest hurdles for diners to get past is the invasiveness of combining sound with the eating experience. Speaking of his work several years ago with Heston Blumenthal at the famously quirky Fat Duck restaurant, Spence recalls being made to wear a headset complete with microphone to enhance the crunch sound heard when biting in to foods such as carrots, in order to inspire a greater taste. “People would sit looking alluringly into their lovers’ eyes, but were then told by the waiter: ‘time to put the headphones on’. It spoilt the moment. It interferes and comes between you and your dining experience.”

Nowadays the Fat Duck opts for a much subtler method – placing earbuds into conch shells. “The dish comes to the table looking like the sea, with the sounds of the sea, with the smell of seafoam – a total multisensory experience,” explains Spence. “It was based on the research we did at the University of Oxford, that oysters taste better with the sounds of the sea.”

Beyond a gimmick though, Spence’s research highlights the impact that external factors can have on the food industry at large. Armed with this knowledge, airlines can plan their menus around passengers’ preference for savoury and umami options onboard. When attempting to trial a new food product in-store, a supermarket could influence consumer reactions by playing the right song on the radio. Studies are still being carried out, but it appears the future of food technology lives in our ears as well as our mouths.