Capturing Audio for Classroom Streaming
Presenting classes online is becoming more common every year. Streaming video of the instructor is quite easy, and using a wireless mic provides great audio from the instructor. In addition, it is rather straight forward to add a second camera to capture video of the students. The challenge, however, is to capture audio of student questions and interaction.
Passing a wireless handheld microphone from student to student creates several challenges. The act of passing the microphone wastes valuable time and stifles lively conversation. In addition, passing the microphone creates unacceptable handling noise.
The best option would be to have a microphone for each student. Each student could be given a wireless microphone, but the cost is quite high. In addition, failing batteries and radio interference can pose serious challenges. A cabled tabletop microphone could be placed in front of each student, but the cost is still high and cable management becomes an issue.
A series of microphones could be suspended from the ceiling, but a large number of microphones are required as the pickup pattern of each is rather small. The cost is lower but can still be rather high, and a significant amount of work is required to hang the microphones.
After a long search for ways to capture audience questions, The Teacher Learning Network (TLN) of Abbotsford, Australia discovered the small parabolic microphone from Klover Products. TLN, which provides professional development courses for teachers, has been using the Sound Shark from Klover Products since 2016. It allows them to successfully capture student questions during their online classes.
While TLN primarily uses a handheld Sound Shark microphone to capture the student questions, it is also possible to hard mount Sound Sharks in a dedicated classroom. Klover Products has tested hanging the small (9-inches in diameter) parabolic microphones from the classroom ceiling at a local, private university. The audio captured with four Sound Sharks mounted in a 20-foot x 40-foot classroom, shown below, was more than adequate with more than 20 students.
In bigger classrooms, or auditoriums, a larger parabolic microphone may be required. While not exactly a classroom situation, the Philadelphia Eagles use a 16-inch diameter parabolic microphone to capture questions during press conferences which they stream live. The online audience complained of not being able to hear the questions before the Eagles switched from a shotgun microphone to the Klover MiK 16 parabolic microphone.
A video comparing the audio captured by the two microphones during a press conference can be found on YouTube. (https://www.youtube.com/watch?v=QkW7k5Mvemk) This same approach used for the press conference can be used to capture student questions in a large room or auditorium.
There are two issues to keep in mind when using microphones of any type to capture student comments. Chatter from the students must be kept to a minimum when the microphones are live. In addition, when the audio from the classroom microphones is ported to speakers in the classroom, feedback will obviously be a very real challenge.
If your institution is having difficulties capturing student / audience comments, parabolic microphones may offer a solution. Contact Klover Products to discuss the options available for your particular situation.
Meet the Author, Paul Terpstra
Paul Terpstra has more than 35 years of engineering and product development experience. He founded Innalytical Solutions, Inc. in 2004, to provide a wide range of engineering services including forensic engineering, Finite Element Analysis, electromechanical design, machine design, and machinery repair. Paul was recently granted his eleventh U.S. Patent.
In April of 2012, Paul and Patrick Santini, an Innalytical Solutions customer, created Klover Product, Inc. Previously in 2011, they had jointly developed a parabolic microphone for Fox Sports when Fox audio engineers grew dissatisfied with the available products. That original test unit turned out to be the first prototype of the microphone that would later become the Klover MiK 26. The Klover MiK 26 parabolic microphones have been used exclusively by Fox Sports for football broadcasts since 2012.