To make sure participants on each side of the call are clearly heard the room needs to provide a good level of speech intelligibility. The key is to control reverberation time and eliminate any unwanted reflections.
Key Hints
Speech intelligibility can be measured and is most commonly seen as Speech transmission index (STI). Reverberation time and background noise are two key components to a good STI.
The following are suggested target reverberation times for meeting rooms:
Small rooms (up to 8 people): RT60 of 0.45s
Medium rooms (up to 11 people): RT60 of 0.6s
Larger rooms (up to 20 people): RT60 of 0.7s
Key Hints
Reverberation Time (RT) is a measure of the rate of decay of sound, helping us quantify how lively or reverberant a room is. RT60 is the time in seconds for a sound to decay by 60dB. A long RT time can hinder speech communication between occupants in the room and for remote participants.
To achieve these targets, acoustic treatment in the room will be required. In existing spaces this might be limited to adapting the wall and floor finishes.
You can look to take advantage of unusually shaped spaces, such as angled, or non parallel walls as they can provide acoustic benefits.