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Better Sound for Better Learning: Beam Steering Benefits in Education

Published: August 1, 2024
Photo credit: Cavan for Adobe/Stock.adobe.com

Speech intelligibility is paramount whether a class is in person, virtual or hybrid. If students can’t hear or understand the instructor, their ability to learn and retain information becomes compromised. Cognitive strain and fatigue quickly set in when students struggle to understand the basic spoken word. In small classrooms, effective communication is made simple, purely due to the dimensions of the space. However, amplified sound is required in a lecture theater, cafeteria or gymnasium where challenging acoustics are inherent in these spaces.

Speech intelligibility can be improved by focusing or directing the sound precisely on the audience and away from areas with disruptive reflections like the ceiling or floors. An excellent solution to address these challenges is digitally steerable loudspeaker technology. It also allows for the listening experience to be tailored in a way that loses no level of quality across that space, sporting several advantages over classic distributed systems. This is made possible with a combination of amplification, DSP, FIR filters, EQ, and delay — all programmed using software.

Intelligibility plays a huge role in learning and information retention. If you’re in a reverberant space like a church or train station and hear muffled speech, you’ll quickly give up trying to understand what’s being communicated. The same is true for students — they become dissociated if they can’t hear and understand the instructor.

Digital beam steering also supports diverse teaching methodologies and activities. By consistently providing intelligible and perceptively high-quality sound, overall academic performance is increased. It also fosters a more inclusive atmosphere where student interaction is enhanced, which is normally reserved for those sitting at the front of the room.

Decoding Beam steering

Digital beam steering is a technique for changing the direction of the main lobe of a radiation pattern from a line array. Beam steering allows the user to focus acoustical output on a specified listening area without physically aiming the loudspeaker.

By directing sound towards the audience and away from other surfaces that may cause reflections, digitally steerable loudspeakers deliver highly intelligible speech and natural music reproduction. In many cases, digitally steered products are the only way to achieve the required levels of speech intelligibility in large reverberant spaces. Eliminating the need to physically tilt the loudspeakers means that digitally beam-steered loudspeakers can often be mounted directly to the wall, hung plum, or even soffit mounted inside the wall, a pleasing by-product for any architectural constraints.

The concept of using an array of loudspeakers to shape sound using beamforming techniques has been around for many years. However, until recently, it has been difficult to put into practice. Dynamically shaping an acoustic wave requires powerful, real-time signal processing, and more powerful DSP has allowed the technology to be used practically for many applications.

Beamforming, beam shaping, and beam steering are terms commonly used to describe the technology. It relies on multiple loudspeakers responding to the same input signal in different ways. By controlling the relative phase and amplitude difference between each element, we can shape the emission pattern according to our needs. The almost infinite number of settings allow the system to control the size, shape and direction of the acoustic wave.

Due to the vast difference in the length of a soundwave at low and high frequencies, there are conflicting requirements for ensuring good performance at both low frequencies (requiring a long array) and high frequencies (requiring dense spacing of loudspeaker drivers). Fulfilling both requirements typically means that the array needs to consist of a relatively large number of loudspeaker drivers that should be controlled individually.

Great Sound for Focused Learning

We should prioritize intelligibility, especially in educational environments. The goal for education sound systems is consistent front-to-back coverage, meaning that people in the front of the room hear the same sound, at the same level, as those in the back.

Clearer delivery of audio content not only prevents possible misunderstandings but also increases student engagement and participation, making lessons more accessible and interactive. Another advantage over a traditional distributed system is that if all the audio content comes from the front of the room, where the lecturer and video are generally, the sound and video will be perfectly synchronized. Unfortunately, sound is a slow medium, and not being able to synchronize the audio and video perfectly means loss of localization on the lecturer or video content.

Using loudspeakers with adaptive directivity — such as digitally steerable arrays — provides you granular control over the audio distribution. The audio improvements can lead to better learning outcomes.


Graham Hendry is VP of Loudspeaker Strategy, AtlasIED.

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