Why Sound Enhancement Is Key to Overcoming the Unique Challenges of English Language Learning Students.
Joseph Havey


300x200 ELL_studentsImagine you’re sitting in the audience of an important educational seminar, and the speaker’s heavy accent makes him difficult to understand. Now imagine beeping cellphones and whirring projectors add to the ambient noise, and on top of that, the speaker has decided to open the windows, letting in the sounds of traffic, birds and lawn equipment. Pretty hard to focus, no?

Welcome to the world of the average English Language Learning (ELL) student. ELL classes are often deprioritized in favor of other subjects, meaning low resources can create an environment that challenges the effectiveness of class time for both students and teachers. Even in an ideal setting, English learning is extremely difficult. 

Screen Shot 2018-11-30 at 9.36.57 AMIt can take between five and 10 years of dedicated study to reach academic levels of proficiency, according to one study1. Coupled with that, ELL students face unique hurdles, such as cultural adaptation obstacles, and they tend to come from low-income backgrounds. To help reduce these challenges, ELL facilities should do everything possible to aid students’ experience by taking into account their unique needs. One of those needs is the ability to clearly hear the teacher. This paper offers an academic look at the listening-based obstacles faced by ELL students, as well as potential solutions such as sound enhancement.


The Problem: Many classrooms are suboptimal audio environments

According to guidelines set by the American Speech Language Hearing Association - (ASHA), ambient noise in the classroom should be no louder than 30-35 decibels when the room is empty, and the signal-to-noise ratio (how much louder the teacher speaks compared to background noise) should be no lower than +15 decibels.

However, research shows the average unoccupied noise levels are much higher, at 50 decibels, and (worse!) average signal-to-noise ratios can be lower than +47 decibels. This is suboptimal for even adults, who require a signal-to-noise ratio of about +6 decibels to hear clearly. The mismatch has severe ramifications on the ability for all schoolchildren -- not just ELL students -- to learn. Lori Hubble Dahlquist of Children’s Care Hospital and School summarizes the predicament: “Oh-oh, the teacher’s starting to talk again. The other kids are going to get what she’s saying but I’m not. I know I’m not going to be able to get it.”

He may not say it, even to himself, but that is often how a child with auditory perceptual difficulties feels when he is asked to listen and learn in the classroom. He can probably hear sounds perfectly well, but he can’t interpret their meaning8.

Screen Shot 2018-11-30 at 9.40.20 AM

Essentially, when children have difficulty hearing, their frustration can lead to disengagement. Illustrating these effects, a 2013 study in the Journal of Urban Health found that 8- and 9-year-old students who experienced higher levels of ambient noise in school performed significantly worse on standardized tests in mathematics and French language, even after controlling for their socioeconomic backgrounds9. Many other studies have found similar results.

In the ELL world, these problems can become even more pronounced.


Why sound enhancement is even more important for ell students:

In 1995, scientists at the University of Florida found a startling result when studying the impact of ambient noise on ELL classroom performance10. To conduct their study, researchers of the University of Florida took two groups of students: one group consisted of native English speakers; the other group was comprised of ELLs.

They then tested their comprehension in various levels of background noise. The results couldn’t be more clear. In quiet settings, ELL students and native English speakers perceived the teacher’s voice equally well and exhibited similar scores on listening comprehension tests. However, when levels of background noise increased, the results diverged sharply. As ambient noise got louder, the ELL students performed proportionately worse than their peers. In other words, the louder the noise, the harder it became for the ELL students to do well in class compared to the native English speakers.

Screen Shot 2018-11-30 at 9.40.33 AMThis study has two interesting takeaways. First, as the authors write, “the finding that ESL children performed as well as the native English speaking children in quiet listening environments suggests that both groups had essentially equal knowledge of the linguistic contingencies of the sentential material used.” That means the divergence in performance was not due to the ELL students’ innate inability to comprehend concepts. Instead, it was entirely due to their difficulties in understanding the teacher. Put simply, the noise was the problem; not the teacher or the students.

Second, in offering an explanation for the differences, the authors underscore a fundamental way in which ELL students’ needs are different from those of native English speakers. The reason that adults require lower signal-to-noise ratios to comprehend speech (+6 decibels compared to +15 decibels needed by children) is that by around age 14, the human ear can begin to rely on contextual cues to fill in the blanks when words are overshadowed by background noise.

If you hear the phrase “Two ____ ____ equals four,” automatically, your brain will fill in the “plus two” section by relying on an understanding of English mechanics. But before 14, most children don’t have enough mastery of the language (native speakers included) to achieve these kinds of linguistic acrobatics, especially when it comes to sorting out the b’s from the p’s or the m’s from the n’s. This challenge is exponentially greater when English isn’t a student’s first language.

As anyone who has tried to seriously learn another language knows, words are so much more than their dictionary definitions. Some words have connotations that differ radically from their denotative meaning (take Bostonians’ fondness for using “wicked” as a compliment, for example), and cultural context is fundamental to understanding phrases and idioms that make no sense when taken at face value. Add in native English speakers’ frequent use of contractions and regional accents, and the problem only gets worse.

Perhaps the study’s authors say it best when they write in their study that “stated otherwise, ESL listeners may need to correctly perceive essentially every word in a sentence in a noisy or reverberant background for optimum communication to occur” (emphasis added). In response to these challenges, some teachers can mistakenly believe the solution is to simply speak louder, therefore increasing the signal-to-noise ratio to adequate levels for comprehension. However, as the next section shows, this has several drawbacks.


Why Talking louder doesn't work:

There are two main issues with using “talk louder” as a solution to students’ comprehension challenges. First, in order to reach the necessary signal-to-noise ratio, a teacher will need to increase his or her volume to levels that are unnatural for the human voice. Because sound gets weaker over distance, some experts believe that it requires a level of 83 decibels to provide the necessary signal-to-noise ratio for students in the back row. This is essentially shouting. As such, it’s little wonder that even though teachers make up about four percent of the working population, they compose about 20 percent of the patient population in voice treatment centers11.

Second, unless you’ve undergone training for public speaking or theater, it’s really difficult to avoid changing your body language and the diction of your words when you speak this loudly. A substantial part of ELL students’ development involves picking up on nonverbal cues; therefore, speaking in such a non-natural way is counterproductive.


Sound Enhancement may be a solution:

Ultimately, the goal for teachers is two-fold: 1) to provide a signal-to-noise ratio that is high enough for students to hear and 2) to avoid distorting the sounds or causing vocal injury by raising their voice to unnatural levels. The best way to achieve this is through sound enhancement technology. Not only does sound enhancement allow the teacher to control the volume of his or her speech electronically, thus reducing the need to shout, it also ensures the sound is distributed evenly throughout the classroom so that the speech is clear regardless of where students are sitting.

To see this in action, consider a study -- also by researchers at the University of Florida -- that examined the impact of sound enhancement technology on ELL students’ comprehension ability. After placing students six, 12 and 24 feet away from the teacher, the researchers saw that comprehension decreased as students moved further away from the front of the room. This is not surprising because, as noted above, a teacher needs to essentially shout in order to reach students in the back row. When the researchers installed sound enhancement technology, these comprehension differences disappeared entirely. The results were statistically significant at the p < 0.0001 level12.

Want more? Several other studies have quantified the vast impact sound enhancement can have on student learning, which you can learn about here.

In summary, research shows that ELL students face unique challenges, including a need to hear essentially every word clearly, as their ability to rely on linguistic structures to fill in the gaps is greatly inhibited. Talking louder is not only unhealthy for the teacher, but it may not even be useful, as it alters nonverbal communication and a person’s diction, unless highly trained.

Instead, join others that have tackled these obstacles with sound enhancement and witness the already proven statistically significant positive results for yourself.


the qball: affordable sound enhancement

While there are many amplification systems out there, the Qball is the most affordable. Only half as much as its competitors, the Qball is a fun way to engage your students and protect your teachers. Visit to learn why Leslie Fisher, over 8,000 classrooms and over 150,00 students trust the Qball.



1 Gustafson, T. J., Au.D. (2011, November 11). Dual Task Performance of School Age Children: Listening in Noise [PPT]. Lubbock: Texas Tech University Health Sciences Center Department of Speech, Language and Hearing Sciences.

2 Johnson, B. (2014, August 22). Auditory Awareness: Are Students Hearing the Lesson? Retrieved August 13, 2018, from

3 Moore, R. E., Ph.D. (n.d.). A Comparison of Acceptable Noise Levels in Children and Adults [PPT]. Mobile: University of South Alabama.

4 Pujol, S., Levain, J., Houot, H., Petit, R., Berthillier, M., Defrance, J., . . . Mauny, F. (2013). Association between Ambient Noise Exposure and School Performance of Children Living in An Urban Area: A Cross-Sectional Population-Based Study. Journal of Urban Health, 91(2), 256-271. doi:10.1007/s11524-013-9843-6

5 Haines, M. (2003). Ambient neighbourhood noise and childrens mental health. Occupational and Environmental Medicine, 60(2), 146-146. doi:10.1136/oem.60.2.146

6 Shield, B. M., & Dockrell, J. E. (2008). The effects of environmental and classroom noise on the academic attainments of primary school children. The Journal of the Acoustical Society of America, 123(1), 133-144. doi:10.1121/1.2812596

7 Klatte, M., Bergström, K., & Lachmann, T. (2013). Does noise affect learning? A short review on noise effects on cognitive performance in children. Frontiers in Psychology, 4. doi:10.3389/fpsyg.2013.00578

8 Enhanced Classroom Hearing - Researching Teacher Preference. (n.d.). Retrieved August 13, 2018, from

9 Comparitive Examples of Noise Levels. (n.d.). Retrieved August 13, 2018, from

10 Titze, I. R., Lemke, J., & Montequin, D. (1997). Populations in the U.S. workforce who rely on voice as a primary tool of trade: A preliminary report. Journal of Voice, 11(3), 254-259. doi:10.1016/s0892-1997(97)80002-1

11 Smith, E., Kirchner, H. L., Taylor, M., Hoffman, H., & Lemke, J. H. (1998). Voice problems among teachers: Differences by gender and teaching characteristics. Journal of Voice, 12(3), 328-334. doi:10.1016/s0892-1997(98)80022-2

12 Blazer, C. (2007, March 01). Improving the Classroom Environment: Classroom Amplification Systems [PDF]. Miami: Miami-Dade County Public Schools.

13 Ibid

14 Ibid

15 Allen, L., M.A. (n.d.). The Effect Sound-field Amplification has on Teacher Vocal Abuse Problems [PDF]. Dubuque: Keystone Area Education Agency.



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