This installment of ‘What Gets Measured Gets Better’ explores the impact of noise and acoustics on our students, educators, and staff in new and existing K-12 school buildings. Noise originates in and around school environments. Common indoor sources include HVAC systems, projector fans, hallway activity, furniture movement, and reverberation caused by hard surfaces (e.g., concrete, tile, glass). In older schools, aging mechanical systems and lack of acoustic treatments often result in higher baseline noise and excessive reverberation times. Outdoor sources include traffic, aircraft flights, rail lines, construction, and community noise. Schools located near highways or airports are especially vulnerable to intermittent high-decibel disruptions that penetrate building envelopes.
Newer schools tend to incorporate improved insulation, quieter mechanical systems, and acoustic design strategies (e.g., absorptive ceiling tiles, wall panels). However, even in modern facilities, acoustics are frequently undervalued relative to energy or ventilation priorities, leaving gaps in performance. To evaluate these conditions, the Coalition for the Advanced Understanding of School Environments (CAUSE) aims to evaluate K-12 schools to better support speech-based learning.
This article serves as a “cheat sheet” to illuminate the importance of evaluating acoustics in learning environments.
1. Listening is Central to Learning
Classroom acoustics and reverberation directly impact learning and wellbeing outcomes, especially for our youngest learners who are developing language skills. When background noise levels exceed recommended thresholds (<35 decibels adjusted in an empty classroom) or reverberation times are too long, speech intelligibility drops, forcing students to expend additional cognitive effort just to understand instruction. This reduces comprehension, memory retention, and engagement.1,2 As schools rightfully prioritize air quality and thermal comfort, there are acoustic tradeoffs that need to be accounted for when districts add fans, rely on natural ventilation, or maintain mechanical ventilation.3
Know the facts: Classrooms with poor acoustics effectively create a barrier to learning, even when instruction quality is high.
2. We Must Stop Celebrating the ‘Teacher's Voice’—It’s Harmful
Seventy-seven percent of U.S. public school teachers are women. They are uniquely susceptible to vocal strain because they have smaller larynxes, or voice boxes, and their vocal cords vibrate more quickly, compared to their male counterparts.4 When we refer to someone using their “teacher’s voice,” it means an educator is straining to overcome noises in and outside the classroom. This is a phenomenon known as the Lombard effect. Over time, this leads to vocal fatigue, strain, and in some cases chronic voice disorders.5 It was estimated that approximately 600,000 U.S. teachers miss at least one day of work per year because of voice problems. Teacher voice injury costs the economy $2.5 billion per year.6 This occupational health concern results in hoarseness, voice loss, increased absenteeism, and reduced instructional effectiveness. The cumulative effect is diminished teacher well-being and retention challenges, particularly in already under-resourced districts. But there is good news, voice amplification technology or portable voice amplifiers have been shown to effectively improve self-reported speech clarity and speaking ease.7
Know the facts: Poor acoustics don’t just strain attention—they strain teachers’ voices, contributing to burnout and long-term health impacts.
3. (All) Language Learners Are Disproportionately Affected
Acoustics is a critical consideration in elementary schools, learning environments with diverse language speakers, and classrooms that have even one student with personal or environmentally created hearing impairments (e.g., sitting near noisy outdoors, ventilation system, fan). Additionally, students and educators with visual impairments will rely more heavily on the spoken word than visual cues.8 Students who are developing proficiency in English or non-native speakers rely heavily on clear auditory signals to decode unfamiliar vocabulary, syntax, and pronunciation.9 Background noise and reverberation distort these signals, making comprehension significantly more difficult. It is essential to reduce classroom noise, increase signal levels, and improve access to spoken language, because English Language Learners have slower language acquisition and increased cognitive load in noisy classrooms. Even small reductions in speech clarity can have outsized effects on these students, as they lack the linguistic redundancy that helps others “fill in the gaps,” often determined by cloze tests.10
Know the facts: Acoustic barriers disproportionately impact English Language Learners, compounding existing educational inequities.
4. Outdoor Noise Exposure Is Not Equal Across Schools
Background noise from outdoor sources influences the indoor learning experience. The geography and surrounding infrastructure create clear disparities across school systems. These schools are often disproportionately attended by students from lower-income communities, reinforcing systemic inequities. Schools located near highways, major arterial roads, airports, or industrial zones experience consistently higher background noise levels. This not only makes it difficult to hear, but it changes teachers’ behavior as well. Studies have found that teachers are less likely to take students outside or open windows due to excessive aircraft noise impacting access to nature, play, and indoor air quality. This is especially concerning for older buildings where operable windows are the main source of ventilation.11 In a study of 106 schools from across Europe, they found that a 1 decibel increase was associated with small, but significant reductions in reading scores and reading test performance and hyperactivity scores increased.12 These outdoor noise challenges may persist regardless of repair, renovation, or new construction status because they are compounded by the age of the building, presence of weak sound insulation, limited funding for acoustic retrofits or voice augmentation systems.
Know the facts: Schools near highways and airports often serve the most marginalized communities, but being responsive to disruptive background noise in these schools buffers the potential for adverse learning environments.
5. Measure and Design for Acoustic Performance
As with other indoor environmental quality factors, improving acoustics begins with measurement and informed intervention. Effective methods include both objective and subjective measures. The CAUSE tool offers occupant surveys that capture acoustic environments, paired with an observation checklist of spatial characteristics that identify key features such as presence of ceiling tiles. Objective measures require monitoring or using sensors to evaluate sound transmission between walls and floors, reverberation times, and background noise levels when classrooms are unoccupied. If you are early in the design process, integrate acoustic considerations when selecting materials, layouts, or mechanical systems. By retrofitting with absorptive materials, sound field amplification, and improved insulation, a district can support learning, protect teacher’s health, and provide benefits to decades of occupants.
Know the facts: Objective measurement paired with user feedback enables schools to identify targeted, cost-effective improvements. You cannot improve what you do not measure—acoustic data is essential for actionable change.
Moving Forward
Improving acoustics in K–12 schools is an equity, health, and performance imperative. When classrooms are designed and operated to support clear communication, the benefits cascade. By integrating acoustic considerations into planning, design, and operations and by prioritizing measurement and continuous feedback, schools can transform into environments where every voice is heard, and every learner has a fair opportunity to succeed. The tools provided by CAUSE are freely available to support your acoustic goals and measurement guidance.
References
- World Health Organization. (2011). Noise. WHO Europe. https://www.who.int/europe/news-room/fact-sheets/item/noise
- Mercugliano, A., Corbani, A., Bigozzi, L., Vettori, G., & Incognito, O. (2025). The effects of classroom acoustic quality on student perception and wellbeing: a systematic review across educational levels. Frontiers in psychology, 16, 1586997. https://doi.org/10.3389/fpsyg.2025.1586997
- Pellegatti, M., Torresin, S., Visentin, C., Babich, F., Prodi, N. (2023). Indoor soundscape, speech perception, and cognition in classrooms: A systematic review on the effects of ventilation-related sounds on students. Building and Environment, Volume 236, 110194, ISSN 0360-1323, https://doi.org/10.1016/j.buildenv.2023.110194.
- Van Houtte, E., Claeys, S., Wuyts, F., & Van Lierde, K. (2011). The impact of voice disorders among teachers: vocal complaints, treatment-seeking behavior, knowledge of vocal care, and voice-related absenteeism. Journal of voice : official journal of the Voice Foundation, 25(5), 570–575. https://doi.org/10.1016/j.jvoice.2010.04.008
- Mogas-Recalde, J., Palau, R., & Márquez, M. (2021). How classroom acoustics influence students and teachers: A systematic literature review. Journal of Technology and Science Education, 11(2), 245–259.
- Long, C. (2016). Teacher Voice Problems Are an Occupational Hazard. Here’s How to Reduce the Risk. Published: June 23, 2016. NEAToday. https://www.nea.org/nea-today/all-news-articles/teacher-voice-problems-are-occupational-hazard-heres-how-reduce-risk
- Farías-Fritz, B., San Martín Cofré, M., Palma Contreras, A., & Roco-Videla, A. (2025). Effectiveness of the use of voice amplification systems in the educational field: A systematic review. Salud, Ciencia y Tecnología, 5, Article 1171. https://doi.org/10.56294/saludcyt20251171
- . Bilal Salih, H. E., Takeda, K., Kobayashi, H., Kakizawa, T., Kawamoto, M., & Zempo, K. (2022). Use of Auditory Cues and Other Strategies as Sources of Spatial Information for People with Visual Impairment When Navigating Unfamiliar Environments. International journal of environmental research and public health, 19(6), 3151. https://doi.org/10.3390/ijerph19063151
- Mealings K, Buchholz JM (2024), “The effect of classroom acoustics and noise on high school students’ listening, learning and well-being: a scoping review”. Facilities, Vol. 42 No. 5-6 pp. 485–503, doi: https://doi.org/10.1108/F-06-2023-0049
- Lam, A., Hodgson, M., Prodi, N., & Visentin, C. (2018). Effects of classroom acoustics on speech intelligibility and response time: A comparison between native and non-native listeners. Building Acoustics, 25(1), 35–42. https://doi.org/10.1177/1351010X18758477
- Montazami, A., Wilson, M., & Nicol, F. (2012). Aircraft noise, overheating and poor air quality in classrooms in London primary schools. Building and Environment, 52, 129–141. https://doi.org/10.1016/j.buildenv.2011.11.019
- Clark, C., Head, J., Haines, M., van Kamp, I., van Kempen, E., Stansfeld, S. (2021). A meta-analysis of the association of aircraft noise at school on children’s reading comprehension and psychological health for use in health impact assessment. Journal of Environmental Psychology, Volume 76, 101646, ISSN 0272-4944, https://doi.org/10.1016/j.jenvp.2021.101646.