The answer to why intelligibility is important for stadium sound systems may seem like a simple one – it’s important for your fans to hear you clearly. But in reality, there is a lot more behind the importance of intelligibility.
While it may seem that intelligibility will be in the ears of the beholder, there are actually empirical methods to measure and test a stadium’s sound system. This is important for a number of reasons, primarily the safety of your supporters and ensuring they can clearly hear announcements in the event of an emergency.
The internationally recognised standard for measuring intelligibility in stadia is the Speech Transmission Index for Public Address (STIPA). This is a Speech Transmission Index (STI) derivative designed to enable fast measurement of electro-acoustic and acoustic environments covering factors that affect the speech intelligibility in the room acoustics and/or public address system.
STI measures some physical characteristics of your electro-acoustic equipment and expresses the ability of this equipment to carry across the characteristics of a speech signal. It is determined and expressed in values from 0 to 1. In order to make sure your stadium complies with regulations from organisations like FIFA, you should be able to achieve a minimum STI of 0.55 for a full stadium with a recommended value of 0.75 – not far off the minimum standard for a recording studio.
Seeing as stadia can present complex and challenging audio environments, hitting these standards can be difficult. However, through intelligent sound system design it is possible to create a solution that will deliver audio at the desired levels.
The first step in this is selecting a high-quality loudspeaker solution. You need a system that will deliver clean and crisp audio in a targeted manner to the desired areas of the stadium. Following this, you need to design the coverage in a way that will provide an even soundfield throughout the stadium, so every spectator gets the same experience. A distributed system comprising multiple flown arrays is the common way of achieving this in larger stadia, but other solutions can work for venues that do not feature a full bowl or lack the necessary support structures for flown loudspeaker clusters.
Prosound prides itself as the go-to stadium sound system designer is southern Africa. From working on the audio solutions at nine of the 10 stadia for the 2010 FIFA World Cup in South Africa, to creating the solutions for numerous national stadiums across Africa, our experienced team has proven itself time and again. Get in touch now to find out how we can help you.