How important are acoustics in university lecture halls?

Sound Zero | How important are acoustics in university lecture halls?

Acoustics in university lecture theatres can be challenging to perfect. They are usually large open spaces and can be occupied by nearly 300 students at any one time. We all know that more bodies in a space can automatically mean more noise.

Learning in university lecture halls, however, is incredibly important. Speech intelligibility, which is the clearness in communication, is a key aspect for considerations into acoustic treatment in a lecture hall space. Students in a room must be able to clearly understand and hear their professor.

Therefore, a lecture theatre space must be designed in a way that maximises the student’s ability to learn and achieve higher grades, even if the lecturer is teaching hundreds of students at once.

What are the problems with acoustics in university halls?

Large spaces of any kind usually suffer from the common issue of high reverberation times, which means noise travels and bounces for too long before it dissipates.

We all know how difficult and distracting it can be to understand someone when background noise is high, but even low-level background noise from reverberations can be significant.

You might not realise how much an impact even quiet reverberations can have on the brain.

The persistent reflection of sound waves causes your brain to constantly be working hard to make sense of your surroundings. Your ears and brain are trying to work together to determine where those sounds are coming from, even if you don’t realise. This causes fatigue and contributes to the loss of concentration.

Poor reverberation and echoes are detrimental to speech intelligibility as well as people’s ability to focus.

Sound Zero | How important are acoustics in university lecture halls?

Poor acoustics can also be detrimental for lecturers at the front of the theatre, as in some acoustic settings where the space is very large, sound can disperse into nothing. When a voice doesn’t carry or is in such an open space it doesn’t return, the speaker feels as if they are too quiet.

They will raise their voice, straining their vocal cords and causing them pain.

All of the issues above are commonplace but so incredibly frustrating for the teachers and pupils in university lecture halls.

Regulations only consider acoustic panels for schools

At this point, you may be thinking, why has no one thought of this before?

Well, architects and designers have thought of this and do understand how important acoustics are in university lecture halls. However, unlike primary and secondary school buildings, universities are not included in the Department for Education’s regulations for the acoustic design of schools.

The Building Bulletin 93 (BB93) states how the acoustic specifications and regulations for schools are desirable for university buildings but are not compulsory. This means that designers can use those specifications as a guide to optimise university acoustics, but do not have to.

This means many university lecture halls across the country may have been constructed with little consideration for sound comfort and noise levels.

However, in such spaces, there are many options for solutions to poor acoustics.

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How to improve university lecture theatres with acoustic treatment?

In order to ensure the large university lecture spaces are optimised, we must pay close consideration to the speech intelligibility of lecturers as well as the reverberation level of the space. We also must consider solutions that work regardless of how many students are in the hall or the size of the space, and still be effective regardless of where students are seated.

Hey, if a student wishes to sit at the back, why should their learning suffer?

If you consider that in a regular classroom, it has been found that children sitting on the back row hear just 50% of their teacher’s words, how can students hear at all in a lecture theatre?

Well, a key element of this is the ascending rows of seating in lecture halls that allow direct noise to travel efficiently to the back of the room. However, we must then prohibit the ability for these sound waves to echo back into the room, off the back wall, through using acoustic treatment on the rear wall. This can be done with sound absorbing acoustic wall panels.

These acoustic panels are so important, but more critically so if the shape of the back wall is curved. This will cause sound to reflect at angles that cause focussing.

The next important element of a lecture theatre is the walls. Where parallel surfaces face each other, sound waves can reflect multiple times, causing flutter echoes and long reverberation times.

Absorptive acoustic treatments on parallel walls will help reduce reverberation and improve the overall acoustic environment in the lecture theatre.

In the lecture theatres where voices don’t carry, we must treat not only the acoustic issues stated above, but must also make sure that lecturers are not straining their voices.

Sound Zero | How important are acoustics in university lecture halls?

We have recently worked in a large space in a secondary school in Leicester, where the extremely high ceiling (over 9m) was causing problems. In this room, the ceiling was covered in polystyrene tiles which are commonplace in commercial and educational building, and they were sucking all the power and volume out of the teacher’s voices.

This issue, combined with parallel facing walls that were reflective and causing an issue with reverb, we had a perfect storm that meant the lecturers couldn’t project their voices enough, and then what speech was heard wasn’t clear.

We worked to provide a solution for this acoustic space through diminishing echoes, controlling reverb, and improving the clearness of projected sound. Using diffusion techniques, and acoustic panels to the perimeter wall and ceiling surfaces, we could deliver an equal dispersion of sound waves to every seat in the room.

Sound Zero | School Acoustics eBook

The background noise is now clean, and the echoes caught and captured, bringing greater clarity to the lecturer and reducing strain for both speaker and listener.

Finally, what about if we have a sound system and the lecturer uses a microphone to reach the back of the room?

Well, we believe that the use of sound amplifiers in a lecture theatre can be extremely beneficial and reduce the strain on the lecturers’ voice. However, we always recommend the use of acoustic treatment as well, especially if the speakers are placed in the walls or on the rear wall.

The sound from the speaker system can still be reflected, the same as before, and the increase in volume will only exaggerate the issues in the room.

If the speaker system is poorly set up and the acoustic space has not been optimised, the speech intelligibility of the room will suffer rather than be improved.

Conclusion: acoustic solutions for university lecture theatres

All of the issues above can be solved with simple acoustic changes such as sound absorption panels and soundproofing.

Treating a university space, such as the lecture hall, is so important for student’s learning and concentration. All speech should be heard clearly and without strong background reverberation.

The benefits of making sure your lecture halls’ acoustics meet – or better this level – presents the opportunity for your students to reach their potential and improve their educational outcomes.

Our team is available to discuss your school acoustics needs to ensure you select the right product from our line. We have a range of products that include moss wallscork panelsinsulation foamacoustic foam, and wall panel pro. All of these acoustic panel options can be completely customised to your colour, size, fabric, and other product requests.

Whether you need maximum noise reduction or slight adjustments to your classroom acoustics, we can help. We have helped countless schools and organisations improve their school acoustics over the years. Please do not hesitate to contact us today to go over our unique acoustic panels for schools that can help your students achieve better focus and attainment.

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