Blood Pressure and Music: A Study

 

Tim Wang, Hanh Tran and Joe Sarr

 

CU Boulder. 2006

 

In the world of product research and marketing, it is a common practice to test the validity of various claims made by companies about their products.  It is important for products to be accurately labeled and deliver upon their assurances so that the customer will be satisfied to the fullest extent.  Albums often sport titles such as “De-stress Music” and subtext that asserts its “stress-free, peaceful and calm” nature.  We therefore decided to examine the claim that music can have an effect on stress levels.  Because stress cannot be easily quantified, we decided to test the response of blood pressure to various forms of music; extensive research has shown that there is a significant correlation between blood pressure and stress.  In this experiment, we tested the effects of various types of music on blood pressure. We hypothesized that blood pressure rises with quicker tempos and “harsher” noises, and decreases with slower tempos and softer tones. 

 

         To test our hypothesis, three subjects took three recordings of our blood pressure with an electric sphygmomanometer while listening to nothing. After establishing the control, we repeated that same method of data collecting, but this time while listening to five types of music. Each of these types of music has a distinct style and tempo. Each listening session averaged on two minutes in length, ending only when the data from the third blood pressure measurement was recorded. After a session, each of us would wait for a period of five to ten minutes to ensure that our blood pressure would return to normal. We would then record our blood pressures again, while listening to different styles of music. Subjects sat down in a chair in a relaxed position while measuring.

 

         The music chosen was of varying genres and tempos. For metal, Dream Theater’s This Dying Soul was chosen, and was the fastest and most aggressive of the selected songs. The sound of the songs focused on creating an uncomfortable and angry mood in the listener, and has multiple instruments playing fast and complex rhythms at the same time. The slowest and calmest song was Unforgiven, a contemporary classical song by cello quartet Apocalyptica, which had a more relaxed atmosphere, and no other distracting sounds other than cellos. The tempos and sounds of the 3 other songs, Haddaway’s What Is Love? (pop), Eric Clapton’s Layla (rock) and The Eagles’ Take It Easy (country) fit inside these two extremes. We predicted that the metal, rock and pop songs would increase blood pressure, whereas classical and country, with their slower tempos and calmer styles, would do the opposite.

 

         Our results indicated that there were no significant differences in blood pressures among the five types of music. Mean blood pressure remained fairly constant throughout the entire experiment (123/79 for no music, vs. 123/78 Metal, 119/76 Country, 126/78 Rock, 121/74 Classical, and 124/78 Pop) and our t tests between groups had p values ranged from p = .26 to p = .41, which are all well above .05.

 

         Our results are inconsistent with our hypothesis. The errors in this experiment may have been due to the fact that the data was collected in a crowded and noisy room, and it was difficult to remain absolutely calm and free of distraction. Another factor that could have skewed the data could have been uncomfortable reactions to the sphygmomanometer. Ultimately, the most crucial source of error may have been the number of people tested. Experiments of this nature often work best when tested upon large groups of people, while we only had three subjects. Other music/blood pressure experiments on the CABLE website have shown different results than ours. Joung et al. 2002 and Thorne et al. 2002 both tested the same general hypothesis, and showed significant differences in their statistics. Unfortunately, neither of these abstracts listed how many subjects were tested, as that may have been the deciding factor in their experiments. They did, however, use different music. Perhaps testing on a much broader scale or with more diverse music will yield different results.