Acoustic Design and Room Function
The Importance of Acoustic Design for Meeting Rooms, Offices, Classes, Auditorium Hall, Schools, Music Hall
We often hear people complain about the acoustics of a room. Complaints such as unclear dialogue spoken by panelists at a conference, music that sounded noisy at a rock concert, could not speak calmly at the dining table in a restaurant due to high noise levels, flight schedule announcements at airport that can’t be clearly heard.
It happens when there is no acoustic consultant being involved in the planning stage of the space, resulting in a room that can’t be used due to acoustic failure, even though it has been beautifully designed.
One of important things to be considered when planning a space that involves audience is the reverberation time and room function. The reverberation time definition can be read in previous article: Sound absorbers for Overcoming echoes in the room: Room Reverberation Time
In this paper I will give some examples of the correct planning for acoustic design – which gives satisfaction to the audience and the owner of the room.
The first example is when designing a conference room – with a maximum audience of 800 people with 80% of the audience’s main activity in the room is listening to speech. Then it is necessary to plan the appropriate reverberation time so that the audience can listen to the clarity and speech intelligibility without any interference of overlapped words due to sound reflections that occur in the room.
Initial room conference room
A good conference room requires a correct acoustic design. Reverberation time is one of the most important aspects of room acoustic planning in a conference room.
The opposite is designing a concert hall – with an audience of around 2000 people with 90% of the audience’s main activity is listening to acoustic music performances.
Orchestras rarely use microphones and loudspeakers. The sound source in the form of musical sounds from the stringed musical instrument, soprano, tenor and so on can be heard well by 1000 audiences thanks to the help of sound reflection and diffusion that has been well designed by the acoustic designer.
Sydney Opera House
Sydney opera house that accomodate 2800 people, one of the orchestral and theater concerts hall with the best acoustic design in the world, has RT and EDT 2.1 seconds.
From the two examples above it can be concluded that there are two basic things that determines acoustic design, which is audience activity and what is the sound source.
What kind of sound that can be heard by audience in a room?
Following are sounds that can be heard by audience in a room:
3. Combination of speech and music
4. Combination of speech, music and noise
Based on the sound listed above, architecs and acousticians classify room function as follows:
1. Conference room: speech
2. Cinema: speech, music and noise
3. Theater: speech and music
4. Pop/rock/jazz performance hall: music with electronic enhancement
5. Orchestra hall: acoustic music without electronic enhancement
6. Worship hall: speech and music
7. Restaurant: speech and background music
8. Night Club: relatively loud music
And based on those list, acousticians globally agree to set both minimum and maximum value of room reverberation time for each room function as follows:
1. Conference room: 0.6 – 1.3 seconds
2. Cinema: 0.6 – 1.2 seconds
3. Theater: 1 – 1,8 seconds
4. Pop music performance hall: 1.4 – 2 seconds
5. Orchestra hall: 1.6 – 3 seconds
6. Worship hall: 1.8 – 3.2 seconds
7. Restaurant: 1.8 seconds maximum
8. Night Club: 0.6 – 1.6 seconds
By following the list of reverberation time above for each space function and combined with the correct planning of the acoustic panel and good interior design, the room owner can maximize the experience of the audience in the room.