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Teaching acoustics to architects in 12 Hrs.: Drinking from the acoustics fire hose

Jeffrey L Fullerton1

Acentech Inc.

33 Moulton St., Cambridge, MA USA

ABSTRACT Teaching acoustics to architecture students is an enlightening position in which to find oneself; teaching acoustics to architecture students within a course period of only 12 Hrs requires a balance of clear organization, concise and efficient delivery, student engagement and the instructor’s ability to adapt. Having taught in this format for several years, experience has shown that organization and efficiency are critical for delivering the conceptual content of architectural acoustics within this short period. Short lists punctuate the key concepts and topics and provide a framework for the students to establish their own organization of the new knowledge. Equally important are engaging the students to require them to think about and apply what they are learning; class participation and a final project, which will be discussed, provide these opportunities. The final important ingredient for success is the instructor’s ability to listen and understand the questions from the students; clarifying confusion and decoding different terminology, injecting relevant experiences and insights, and using analogies and anecdotes all reinforce the learning process. While this short course length is not advisable or desirable, the approaches discussed help make the time most effective for the students’ ability to succeed at being more aware of acoustics. Keywords: Teaching, education, architecture students

1. INTRODUCTION The opportunity to teach is an opportunity that one should not to allow pass. Beyond the

obvious benefits of helping enlighten others with new insights and skills, teaching to others tends to force the instructor to examine their own knowledge and understanding of the topic and how to best convey it to the students. Finding ways to organize and present the topic in a logical progression that allows the pupils to understand the content is important. Equally critical is providing examples for the pupils to experience or explore the topic beyond their initial exposure, as these experiences and explorations allow the pupil to gain further insights that are for them empirical and help to create a lasting knowledge.

These objectives are even more critical when the time with the students is extremely compressed. In my current role as an Adjunct Instructor for the Boston Architectural College, the class time with the students for the acoustics section of the Acoustics and Lighting course is a total of 12 hours, divided into 4 nights of 3-hour sessions (note the Lighting portion of the course also consists of the same period of class time). This relatively short amount of time to engage the students is challenging, since the time allotment leaves scant time to cover the topics in class together, while 1 jfullerton@acentech.com

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also integrating exercises to assess the learning process and exploring the topics beyond the reading assignments and the class discussions.

In practice, this schedule does present limits, but also opportunities. Over 4 years and 16 classes of students, I have witnessed how certain techniques can help the students connect and understand the materials of the course to a greater depth than when they started. Many students cite their appreciation for having had the chance to learn a topic that they hadn’t originally discovered or experienced. This paper will highlight the primary techniques that have demonstrated a sense of increased engagement, inspiration and accomplishment by the students.

2. COURSE GOALS As part of the background for this discussion, it is useful to clarify that the course is a

requirement to fulfill their Technology & Management credits for graduation; from this perspective, the students are required to enroll in the course, whether they are interested in the topic or not. One could say that such a requirement sets a positive expectation for providing a broader perspective of the environmental conditions to these architecture students that they should apply to their future designs. However, it could also be said that requirements do not inspire a true interest in any topic. It is for this reason that the instructor needs to inspire a passion for learning the topic so that the students’ exposure is lasting and influential to their future design work.

With this context in mind, a review of the course goals was important given the scheduling challenges. To begin, I find it is critical to ascertain the students’ previous experience and future engagement with acoustics in considering the end goals of the course. These two topics are discussed in more detail below.

2.1 Acoustics as a new Topic/Subject The class roster is typically between 8 and 16 students, who may be either undergraduate or

graduate architecture degree candidates. The classes are generally small enough to start with a 10-15 minute period of introductions. At the beginning of each new class, each student describes the following:

• What types of architectural project experience they have; • What experience have they had with acoustics or music; • What they hope to learn from the course.

From these inquiries, I gain some insight to the students’ prior experience, or lack there of, with architecture and acoustics. It also provides me with an understanding of the unique perspectives that the students bring to the class. Based on this feedback, I have found that the potential range of backgrounds and experience can be rather large and often extremely varied, with some students having worked in architectural firms and had initial acoustical experiences on past or existing projects and other students having no prior exposure to acoustics. These insights introduce the first significant challenge: charting a syllabus that engages and inspires the students who are new to acoustics, while expanding the knowledge of the students who have prior experience. Often, the compromise of this challenge is to introduce the new students to the topic, while providing a forum for creating a deeper sense of understanding, and occasionally correcting misunderstandings or misconceptions, for the more experienced pupils. This balance helps advance the wide range of backgrounds that the students present.

With regard to the students’ objectives for the course, they tend to have similar objectives: • a greater understanding of how acoustics and architecture interact; • learning how the acoustics influence the occupants’ experiences of a building, and • the ability to understand the various acoustical terminology and acronyms.

These objectives are an appropriate place to start, as understanding these interactions and the terminology are critical to their future engagement with the topic on upcoming projects.

2.2 Students to be Architects, not Consultants/Scientists As described above, the students of this architectural course do not bring a common background

of education or experience. Given a combination of the wide range of mathematical backgrounds, different past exposure to acoustics and the limited amount of course time, the objective of the course is for the students to have a greater exposure to acoustics as it relates to architecture for applying to their future careers as architects and designers. Admittedly, this is a far different objective than teaching engineering students who may become future scientists or consultants that

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would need to use a more in depth level of technical knowledge on a day-to-day basis. As a result, I have found a more efficient structure to the syllabus involves instructing the students to understand a variety of key principles and examples that are most relevant to their future awareness and understanding as architectural designers, but not to emphasize the more complex topics such as logarithmic math involving decibels. This reduced scope allows for greater emphasis in the areas of acoustics where these designers are most likely to need their acoustic training.

The key principles taught during the class include the basis for many of the important foundations of understanding acoustics. These are imperative to cover in a logical progression from concept to applications in real life, so that the students have the building blocks for future exploration within the topics. Examples of the key principles that are covered include:

• Addition of two similar sound levels (in dB) and when sound levels are not additive; • Human perceptions of sound level changes; • Relationships between sound levels and hearing damage; • The decay of sound over distance (this can be related to the first topic by discussing

spherical spreading) • The relationships between sound power and sound pressure and what factors relate the

two; • Difference between room acoustics and sound or impact insulation (very important!); • 3 primary types of sound absorption; • Uses of sound absorbing, reflecting and diffusing finishes for improved room acoustics; • How reverberation is calculated and general ranges for different spaces; • Primary factors for improving sound and impact isolation; and • Various acoustical requirements and guidelines that might apply to their projects.

By reducing the scope of the course to this more manageable list, there is a greater chance for the students to understand and retain this information that they are exposed to. This list also allows sufficient time to cover these topics in depth within the short time frame, providing time for repetition and individual questions.

As mentioned above, the topics focus on architecturally related issues that the students will most likely apply on their future projects. The topics do not include in depth discussions of the generation of noise and vibration from mechanical systems, since the detailed understanding of the generation and control of noise from mechanical systems does not easily fit into the limited timeframe of the course. That said, this is not to say such mechanical system noise and vibration are not discussed; this topic is covered, but in the context of how this noise and vibration relates to the architectural design. More comprehensive coverage of this topic would provide the architecture students with greater understanding of how these systems might impact their projects; however, this would also require additional class time in order to effectively engage students. Ultimately, given that this topic is not a primary focus of their future careers, reducing the focus on this subject during the course was an effective approach for developing a syllabus that could be accomplished with the allot course period.

3. RESOURCES A variety of different resources are used in the class. The two primary resources are the

textbook and an online class tool.

3.1 Textbook The text for the course is Architectural Acoustics by David Egan [1,2]. I have found the book is a

good balance of an introduction to the math and science of acoustics combined with an extensive amount of graphic details and visual aids to explain and convey the information clearly. Through their study of architecture, many of the students have strengths with understanding visual and graphical information, which this text does well. The textbook is also a good reference for acoustical information that the students can use in their future as designers. The students are encouraged to purchase the book (prices vary between about $50 for the newer paperback version and $70 to $100 for the original hardcover edition), but several copies are also available in the College’s Library. There are even portions of the text available through Google Books, though it is not a full copy.

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3.2 Internet Class Tool The Boston Architectural College has created a series of courses that are described as “hybrid”

courses, because they utilize both face-to-face class time along with having an online presence. The College hosts their online courses through a internet tool called Moodle, which provides a range of useful features. The Moodle course site is designed by the instructors and is a secured, invite-only site that is shared with all of the registrants to the course. The site provides a number of standard features, such as:

• The ability to create weekly lesson plans (viewable by the students on a week-by-week basis) where discussions on the week’s topic and assignments can be posted;

• File hosting for documents, such as the syllabus, references, and web links (accessible for viewing or download); and

• Messaging to the class as a group to deliver announcements. Moodle offers several advanced features that are also useful for the instructor and students.

Through Moodle, online quizzes can be set up with features that allow the student to take the quiz, while having time limits and with the ability to change the order of the questions. There is a forum feature that can be used to allow discussions to occur outside of class (we do not utilize this feature). The Moodle site also provides a means of entering and calculating grades, which are available for view by the student as the grades are entered. This helps the students understand their progress with the course, if they are interested.

4. STUDENT ASSESSMENT To assess student engagement and performance, the course includes three types of graded

elements. They are weekly quizzes, a final quiz, and a final project. Each weekly quiz constitutes 10% (together 30%) of the acoustics grade, while the final quiz represents 20% of the acoustics grade. The final project consists of 50% of the acoustics grade. All of these are combined together and added to the grade from the Lighting portion of the class for the final grade of the course.

Each of these grading elements are described in more detail below.

4.1 Weekly Quizzes Weekly quizzes are given to ensure that the students are attending class, reading the assignments

and following the class discussion. The quizzes include 10 multiple-choice or True/False questions about each week’s reading assignment and discussion topic. The multiple-choice questions are worded such that they require the student to carefully consider the reading and discussion to arrive at the correct answers.

4.2 Final Quiz The final quiz is a longer version of the weekly quiz with particular emphasis on testing the

students’ understanding of the acronyms used in the industry. Specifically, the students must relate the acoustical property that is defined by several of the acronyms that are commonly used in the industry. This is intended to confirm that they understand how the acronyms apply to the acoustical conditions that they will face in the future. Other questions on the final quiz test their understanding of the key principles in hypothetical situations.

4.3 Final Project The final project is an opportunity for the students to express their creativity in a more

open-ended manner. The problem they face is to choose to design one of 4 types of spaces within a large empty space at a university:

• A café with live music, • A multipurpose auditorium, • A music recording studio, or • A suite of student organization meeting rooms, including a band practice room.

After choosing a design that they are interested in pursuing, the expectations for the submission of the project include:

• a narrative of the acoustical goals and conceptual approaches for the chosen design; • drawings showing floor plans, reflected ceiling plans and sections or elevations

highlighting the acoustical aspects of the design;

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• partition details and door schedule showing the acoustical features; • a detail of how to handle penetrations where utilities must pass through a construction;

and • information sheets of the products that are planned in their design, with specific details

highlighting the products’ acoustical performance. The final project allows the students the ability to demonstrate their understanding of the

acoustics from the reading and class discussions through a creative and freeform exercise. As with the rest of the class, the difficulty with the final project is the short time frame for which

to complete the submission. To help convey the importance of starting early on this assignment, numerous prompts and reminders are provided during each class. For example, after the first class, the students are expected to think about and select the type of space they want to design; this selection is presented at the start of the second class. At the conclusion of the second class, which focuses on sound absorption and room acoustics, the students are urged to start thinking about the interior finishes of their space and developing goals for incorporating these finishes. After the third class, which focuses on sound and impact isolation, they have the last week before the fourth class to summarize the remainder of the issues and produce the project submission.

Over the years, the final project submissions have ranged in quality from very detailed and thoroughly coordinated designs with elaborate explanations to projects that lacked explanation of both room acoustic and sound isolation features. The submissions have generally demonstrated that the students are able to apply their knowledge from the course in effective ways that benefit the acoustics of the design. The students have presented some very creative approaches and innovative solutions to the acoustics concerns on their projects.

5. TEACHING TECHNIQUES Once the goals of the course are developed, I have witnessed several techniques that have helped

increase the students’ engagement and retention of the knowledge. Three techniques that I have employed have included lists, analogies, and repetition.

5.1 Organized Lists Well-organized lists are useful and important tools for helping with the retention of the topics that

are covered in the reading and discussed during class. The lists might include anywhere from 3 to 7 items on a specific topic. Through these lists the students are able to organize specific details of the discussion into logical and digestible content that is easy to access and remember. These lists might be as simple as how to categorize the potential acoustical concerns on a project (room acoustics, sound & impact insulation, and background sound levels) to a list of the various factors that help improve sound & impact insulation. By developing and discussing these lists, the students have an organized reference to return to for reviewing their understanding of the topics.

5.2 Analogies Ralph Waldo Emerson, a fellow Bostonian who preceded me by nearly 200 years, is credited with

having said [3]: “The man [or woman] who can make hard things easy is the educator”.

While acoustics should not be portrayed as a “hard thing”, it is often a new topic for architecture students. Given this starting point, it is the educator’s role to devise how the topic can be conveyed most effectively for the students’ understanding.

The understanding of new concepts can be improved by introducing relationships between the subjects that are to be taught with topics that people are already familiar. Such relationships may represent helpful analogies for understanding new information within the context of an already understood concept. For example, when teaching an understanding of sound power versus sound pressure, it is useful to discuss the analogies of these to lighting, which is taught in the first half of the course. Presumably in the Lighting portion of the course, they were taught that the light generated from a light bulb of a given wattage is a consistent light source, but that the light seen by one’s eyes are determined by many factors, including: distance, reflectors (around the light bulb) and the surrounding boundary conditions. These factors are shown in the Figure 1 below. By using this analogy the students can relate to their experience with light, which should be very familiar to them. This analogy helps them to understand that distance from the bulb (represented by the arrow Figure

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1) reduces the brightness, reflectors around the bulb (represented by the angled line above and to the left) intensify the light, and the boundary conditions (represented by the dashed border) can affect the ability of the light to dissipate or reflect. One can elaborate on the effect of the boundary conditions by asking the students to envision the light from the same light bulb when placed in a room full of mirrors compared with a room that is painted flat black; through this analogy it is not uncommon to see students have their own light bulb turn on, when they recognize how the boundary conditions for light and sound relate. Ultimately, by using this analogy to light, the concepts of acoustic power and pressure can be more easily understood and retained by the students.

Figure 1 – The left hand figure shows the factors that affect the magnitude of light seen from a light bulb

(distance, reflectors, and the boundary conditions), which are analogous to how sound is affected by the

same factors, shown on the right hand side. Likewise, an analogy can be made with human perception to temperature in degrees Fahrenheit

and sound levels (unfortunately, this analogy may not convert well to metric temperatures due to their different scale). In this analogy, people familiar with the Fahrenheit scale can empirically relate to a 3°F change as “just noticeable”, while a 10°F change in temperature will typically change one’s selection of clothing; this relationship is useful to establish, as now the students can more clearly understand how one might react to simple changes in sound level through their own experience with temperature.

But while it is useful to develop such relationships to simplify the students’ understanding of the topics, it is equally important with these, or any, analogies to clarify any assumptions that might make such simple relationships invalid. For example, with the temperature analogy, it is necessary to clarify that the only factor that is being changed is the temperature and the sound level. Other changes, such as air movement, humidity or exposure to direct sunlight are not accounted for in this simplified version of the relationship; these factors would affect temperature similarly as would changes in the spectral character, temporal sound level variations and spatial characteristics would affect sound levels. As a result, it is necessary to understand how such analogies are simplified and are easily made invalid by other factors. So as much as simplifying can help illustrate the point, the assumptions behind the simplifications need to be highlighted to avoid confusion when the students envision different conditions.

5.3 Repetition Even with the previous two techniques, another important factor for helping the students retain

knowledge is to repeat the important topics several times. The first introduction to the topic is through reading assignments to be accomplished before the class. Through the period of each class, the second exposure to the topic helps to review the information and allow the students the time to ask questions about the concepts. After covering the topics during class, a quick review of these topics can be performed by asking them questions to confirm their understanding or correct any misunderstandings. In the last class, a final review of the topics covered can be accomplished by asking the students to help fill in the lists of different details that were covered on the various topics. For example, one of the more difficult concepts for some students can be differentiating between the acoustical issues associated with room acoustics and sound & impact insulation. While this topic is clear and distinct for us, many students require repeated exposure to retain the understanding that

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room acoustics relates primarily to surface finishes and sound & impact insulation is affected mostly by the constructions that separate spaces. To ensure that the students have sufficient exposure to this concept, this topic is introduced in the first class and repeated in all 3 of the following classes. The repetition helps to drive home the concept for students who otherwise have difficulties understanding the difference between the two issues.

6. CONCLUSIONS Instructing an acoustics course for architecture students is an exciting role to perform, but having

the course time limited to 12 hours is a significant challenge. By setting reasonable goals for the student learning outcomes, the breadth of the topics can be consolidated to the issues that are most relevant for the students. It is important to utilize a textbook that includes visually effective graphics and an online class tools can help the student engage with the topic and view their progress in the class. Assessing the student performance is accomplished through a combination of weekly quizzes, a final quiz and a final project that allows the student the chance to demonstrate their knowledge through their own creativity. Student engagement and knowledge retention is helped by employing time tested techniques that involve organizing the topics into clear and logical lists, utilizing analogies of new topics with topics that the students are familiar, and repeating the select concepts to emphasize the important key principles of the course. Through these different approaches, I have experienced that students can respond with inspiration and interest for the topic of acoustics and have lasting knowledge for their future design careers.

REFERENCES [1] M. David Egan, Architectural Acoustics (McGraw-Hill, New York, New York, 1988). [2] M. David Egan, Architectural Acoustics (J Ross Publishing Classics, Fort Lauderdale, Florida, 2007). [3] http://www.rodneyohebsion.com/emerson.htm