“Welcome to study hall. Ladies and gentlemen, please engage in a quiet activity.”
Our study hall is suitable for anything but studying. It’s great for an energetic game of poker, sharing scandalous gossip, and watching funny videos on Youtube (if you don’t need to be able to hear them). Our cafeteria is very loud during our spare periods.
Last year at this time, only grade 12 students had spares. However, due to our school’s overpopulation issue, action was taken to put science classes in science labs and up to two gym classes in the gym at one time instead of three or four. Many students were excited by this change. For some, it meant that they could sleep in longer. For others, it meant they could take a two-hour lunch break. Certainly, nobody complained about the early dismissal on Fridays. But what do you do with the fifth of the school who have been removed from classrooms? Our solution was to create a study hall. It was a great idea in theory.
The problem is, if you put nearly 400 teenagers in a single room with one adult supervising in a corner, it will take supernatural powers to keep the room quiet. We already know it’s too loud to study for most people, but The Reckoner wanted to know: is it so loud as to damage our hearing?
To find out, I borrowed an analog sound meter probe from the science department and took some measurements. Measurements were made each day during period 4 spare from five locations: the four corners and the center of the cafeteria. The device was placed on a table with the sensor always facing the center of the room. Here is the data showing the localized sound levels:
It is interesting to see the quietest section of the study hall is in the southeast corner—the corner usually under direct view of an angry vice-principal. Opposite in the northwest corner is the loudest location in the room, the data shows.
Here is the data showing the average sound levels of all five locations from each day of the week:
It appears the cafeteria is loudest on Fridays, no surprise there. Thursday and Tuesday have lower readings likely because they were the 27th and 29th respectively. This meant that period 4 spare was the last period of the day, resulting in noticeably fewer students in the cafeteria at this time.
According to the Canadian Center for Occupational Health and Safety, in Ontario the maximum permitted exposure level for 8 hours is 85 dB. The average sound level of the cafeteria during period 4 spare this week was (78 ±4) dB. This is actually a safe volume of sound to be exposed to; we are not in the cafeteria for such a long duration and the average sound level is not quite high enough to be a health concern. For the noise exposure to be a health risk for the one hour and fifteen minute spare duration, the noise level would have to be in excess of 100 dB, the same as the volume of a chainsaw from a meter away. Since sound levels are logarithmically scaled, this is about 20 times louder than our current exposure.
Fortunately, we are not likely to acquire hearing loss from being in the cafeteria during spare. Regardless, you will probably find it too loud to study in peace. For the study keen, there is unfortunately no quiet space available in the school. But to reduce noise levels, one thing which may help is putting the vice-principal’s desk in the center of the cafeteria. This would allow the vice-principal to hear more of the cafeteria than from just one corner.