Heart transplants are sometimes performed on rodents, with the aim of testing anti-rejection drugs. But that鈥檚 not what researchers at Teikyo University in Japan had in mind when they performed the operation on a group of male mice. They were interested in studying how the animals responded to different types of music piped into their 鈥渞ecovery rooms.鈥� This is not as outlandish as it might sound. Music has long been thought to have therapeutic properties.
The book of Samuel in the Bible tells us that 鈥渨henever the evil spirit from God came to Saul, David would take the harp and play it with his hand; and Saul would be refreshed and be well, and the evil spirit would depart from him.鈥� The evil spirit was likely depression, and modern studies have corroborated the beneficial effect of music on levels of cortisol, the stress hormone. Undoubtedly undergoing a heart transplant is a stressful situation. Indeed, studies have shown that human patients who listened to music during and after open heart surgery required shorter intubation times. Such studies raise the question of whether different types of music lead to different outcomes and that is precisely what the Teikyo researchers aimed to find out.
The study was carried out in a proper scientific fashion with mice exposed to Verdi鈥檚 La Traviata, a selection of Mozart sonatas, or songs by the Irish singer Enya being compared with a control group. I would have liked to see another set of mice forced to listen to some loud rock, like the eardrum-bursting sounds that are blasted at spectators at hockey games at the Bell Centre the instant there is a stop in play. But that would probably have been too cruel. In any case, the results of the experiment were interesting. Mice that listened to Verdi or Mozart lived an average of twenty days longer than the animals that suffered in silence or the ones exposed to a single frequency tone. For some reason, the immune system of these animals was much more likely to reject the foreign tissue. Enya鈥檚 songs were not much of an improvement over no music. It鈥檚 hard to know what to make of such a study, but the mice may find some frequencies irritating, some pleasing 鈥� much like people do.
Manufacturers of Crystal Singing Bowls claim that people, like mice, also respond to specific notes and that 鈥渉ealing frequencies鈥� can be generated by circling the rim of the bowl with a suede-covered mallet to produce an enchanting sound that eliminates the 鈥渄isharmonious conditions鈥� that cause disease. I can鈥檛 get in tune with that. When it comes to health effects, I think people are far more likely to respond to music based on what they like rather than to specific frequencies. I know I would enjoy treatment with Andrew Lloyd Webber鈥檚 Music of the Night (especially if performed by Michael Crawford) a lot more than being abused by the sounds of Limp Bizkit.
It seems that in my music preferences I may have something in common with egg-laying hens. British farmer Steve Ledsham was surprised when his chickens started laying eight eggs a week instead of the usual four. What was different, he wondered? The increased production seemed to coincide with the building of a new barn, suggesting it might have had to do with the music that was being played to entertain the workers. Ledsham now plays Webber鈥檚 music all the time, and as he says, his farm 鈥渋s overrun with eggs.鈥� Soothing music, he feels, relaxes the birds and the calming effect increases egg production.
It isn鈥檛 only chickens that perform better with music. It seems that cows produce more milk when they listen to calming music. And that isn鈥檛 just hearsay. Researchers at the University of Leicester in the U.K. exposed herds of Friesian cattle to different types of music for twelve hours a day over nine weeks. On days when slow music was played, milk production increased by about 3 per cent. Beethoven鈥檚 Pastoral Symphony and Simon & Garfunkel鈥檚 Bridge Over Troubled Water were a big hit in the milking shed. On the other hand, the cows did not enjoy Size of a Cow by Wonderstuff. The music is pretty objectionable, and the cows probably did not think much of the lyrics, either: 鈥淒amn blast, look at my past, ripping up my feet over broken glass. Oh wow, look at me now, I鈥檓 building up my problems to the size of a cow.鈥�
A Moo Down Milk Lane has no lyrics, but this original composition by Tzu-Deng Jerry D was judged to be the winning entry in a contest run by the British Columbia Dairy Association. The challenge was to come up with music that best increased milk yield, and apparently the cows really enjoyed Jerry D鈥檚 dulcet tones. I wonder how the food that the cows chomp on would respond to this little composition. Yes, believe it or not, plant growth may also be affected by music. In 1973, Dorothy Retallack published a book titled The Sound of Music and Plants, in which she described her experiments that involved exposing plants to different types of music. 鈥淓asy listening鈥� sounds actually made the plants lean toward the speaker, as if hungering for more. Rock music, on the other hand frightened the plants, stunted their growth and caused them to seek refuge by leaning away from the speaker. The plants didn鈥檛 care for country music one way or another, but interestingly, they did have a preference, in terms of instruments. Strings, particularly the sitar, were favoured over percussion instruments.
How can such a response be explained? Consider that as far as we are concerned, sound is the brain鈥檚 interpretation of the vibration of our ear drums in response to variations in air pressure. It is not inconceivable that such changes in pressure can have an effect on the movement of plant cells, resulting in changes in growth. This is more theory than hard science, but some vintners are convinced enough to have placed speakers in their vineyards exposing the vines to the soothing sounds of Mozart and Vivaldi. I wonder what some of Justin Bieber鈥檚 warblings would do. Maybe keep birds and insects away. There鈥檚 an experiment waiting to be done.
