In the popular hybrid business environment of today, meeting participants are no longer all together, in the same space, but can be connected from anywhere, even improvised environments! How do you make sure that all attendees can collaborate better? Bose Professional offers its point of view…
Audio is the main weakness in hybrid meetings, for two reasons: the first is the poor microphone receptivity for remote participants, while the second is the poor quality of the speakers for the in-person participants, who often cannot hear those who joined remotely. And if the audio signal isn’t clear, no video or screen sharing will be able to save the meeting. Bose Professional’s goal is that all participants should be clearly heard and understood. In acoustics it is called “speech intelligibility”, referring to the frequency range of speech and its understanding by the human ear. Based on some in-depth research done by Bose Professional, today we break down the most common acoustic challenges and some techniques that can help overcome them.
First of all, we start from the awareness that sound behaves remarkably similar to light and it’s useful to use light to visually explain how sound interacts with various types of spaces and environments. For example, light and sound are reflected from certain types of surfaces – in the case of sound, from hard and rigid surfaces such as glass, tiles or wood, which cause various kinds of annoying echoes. Even rough or uneven surfaces can absorb or diffuse sound in incorrect ways. Reflection, critical distance, absorption and diffusion are the key dynamics to be considered when evaluating a particular meeting place. The structural elements of each room, after all – walls, floor and ceiling – generate sound reverberation. Solid materials often cause sound waves to bounce, and complex room geometries can cause variations in reverberation time depending on the direction of the sound source.
The simplest remedy for staying within critical distance and fighting room reverberations is to keep attendees within a ten-foot radius and use a directivity microphone to detect the audio source. A device like the Bose Videobar VB1, which includes an array of beamforming microphones that track people speaking in the room and remove echoes from reflections even up to six metres away, are particularly suited to addressing these issues. For meeting rooms with high ceilings (up to five metres) it’s recommended to use absorbent materials as an acoustic remedy. For example, carpet is perfect for large venues such as theatres and concert halls, as well as large meeting rooms. Sound absorbing curtains are also indicated, or acoustic foam panels designed to absorb sound energy in the frequency range from 500 Hz to 4 kHz, in which most of the reflection on speech occurs.
Just as important as absorption, diffusion is not as simple. Diffusers come in a large variety of shapes, but the most common are small squares arranged in a pattern on a panel, rounded or cylindrical columns and panels. As with other acoustic treatments, specific sizes and shapes are related to equally specific frequency bands. More active solutions are also available, including the EdgeMax EM180 speaker. Its wave guide, which manages the directional propagation of sound energy, keeps that energy away from reflective surfaces such as walls or windows and can reduce the need for passive acoustic treatments such as absorption panels. Similarly, the Bose Videobar VB1 uses the aforementioned beamforming technology along with proprietary speaker transducers that reproduce accurate and immersive audio.
