Concert Hall Acoustics Design

Concert Hall Acoustics Design

Introduction

Michelle Visa introduces herself and the topic of concert hall acoustics research and design. She explains that the primary goal is to link quantities about sound to human perception.

Science of Concert Hall Acoustics Research and Design

  • The goal is to improve design by linking quantities about sound to human perception.
  • Architectural features such as reflectors, shaping of walls, and materials affect how sound bounces or reflects around a room.
  • Sound field measurements or simulations are used to quantify sound in order to better design space for good acoustics.

Perception of Good Acoustics

Michelle discusses how people perceive good acoustics and the need for a set list of vocabulary attributes that contribute to overall room acoustic impressions.

Attributes Contributing to Overall Room Acoustic Impressions

  • People use different terminologies when describing what makes good acoustics, such as texture, warmth, balance between orchestra, etc.
  • A set list of vocabulary attributes needs to be established in order to better understand what contributes to overall room acoustic impressions.

Reverberation and Clarity

  • Reverberation is the sense of how long it takes sound - how sound lingers in a space. It contributes positively towards good acoustics.
  • Clarity refers to being able to hear individual instruments clearly while still having reverberation present in the hall. It also contributes positively towards good acoustics.

Envelopment

  • Envelopment is the sense of the sound surrounding you in all directions which contributes positively towards good acoustics but has not been studied well yet.

Reflections in Space

Michelle explains how reflections in space are quantified and how they contribute to envelopment.

Sound Decay Over Time

  • Sound decay over time is used to quantify reflections in space. The first sound heard is the direct sound, followed by sounds that reflect off individual surfaces.

Envelopment and Reflections

  • Preliminary research has shown that we need to know when the reflections arrive at the listener and what direction they come from in order to better understand envelopment.

Envelopment and Reverberation

The speaker discusses how reflections contribute to envelopment and the importance of studying reverberation in different types of halls.

Reflections and Envelopment

  • As time continues, reflections start to get lower in level, contributing to reverberation.
  • Cathedra can be used to study the contribution of sound decay to envelopment.
  • A special microphone is needed to measure sound in 3D for reproduction.

Studying Reverberation

  • Measurements were taken from eight local halls with varying sizes and acoustic properties.
  • Participants rate different concert halls using a tablet with a slider faller.
  • Early sound starting from about 60 milliseconds contributes more than previously thought.

Special Microphone for Measuring Sound

The speaker explains the use of a special microphone for measuring sound in 3D.

The Sphere Microphone

  • The sphere microphone has 32 half-inch microphones evenly distributed over it.
  • It was developed by Penn State grad Gary Elko and captures sound coming from all directions.

Directional Sound Contribution

The speaker discusses the directionality of sound contribution to envelopment.

Sound Directionality

  • Energy coming from plus or minus twenty degrees or in front contributes most to envelopment.
  • Designing for architectural spaces with higher envelopment requires knowledge of when and where reflections are arriving.

Measuring Acoustics

In this section, the speaker discusses the importance of measuring all types of halls and not just ones with excellent acoustics. They want to have a range of acoustics so that people can evaluate them in terms of preference and see how much envelopment, reverberant, and clarity factored into their overall preference.

Importance of Measuring All Types of Halls

  • The goal is to measure all types of halls, not just ones with excellent acoustics.
  • A range of acoustics is needed for people to evaluate them in terms of preference.
  • Envelopment, reverberant, and clarity are factors that need to be considered when evaluating acoustic preferences.

Supporting Graduate Students

In this section, the speaker mentions their desire to support graduate students. They also acknowledge the work done by two graduate students who helped with the project and thank the National Science Foundation for funding it.

Supporting Graduate Students

  • The speaker wants to support graduate students.
  • Two graduate students named David Dick and Matthew Neal helped with the project.
  • The project was funded by the National Science Foundation.
Video description

Concert Hall Acoustics Design - Combination of Architecture, Psychology, & Engineering - Michelle Vigeant The successful design of concert halls is often a delicate balance between having innovative architecture and still achieving excellent hall acoustics. Many perceptual attributes contribute to the overall impression of excellent acoustics. For example, “reverberance” – the perception of sound lingering in a space, “clarity” – the degree to which you can distinguish between individual notes, and “envelopment” – the sense of being completely surrounded by sound. However, there is a gap in our understanding of the importance of each of these characteristics to the overall room acoustic quality. Researchers at Penn State are studying this topic to develop new design guidelines to improve future concert hall designs. Measurements have been taken in several regional halls and plans are underway to measure well-known halls throughout the United States and Europe. Using these measurements, listening tests are being conducted in a special listening facility on campus that has 30 loudspeakers that are installed in an anechoic (no-echoes) chamber. The relationship between the measurements and the listening tests are then evaluated to identify the influence of hall shape and surface finishes on the acoustics. These results will ultimately inform future designs, which will improve the quality of the concert experience for attendees and may also result in more cost-effective halls.