A newer term than conference room is the huddle room, which is a temporary place for conducting a conference call that is not a formal conference room. The huddle room can be a small area such as a table off to the side of a larger room, or it can be someone's office.
A huddle room is a location where team members gather together to strategize, motivate or celebrate. You could place your cell phone on the table with the speaker turned on in a huddle room. This can work, but usually not very well. Learning a bit more about audio can help improve huddle room sessions.
The trend is moving away from large board-style conferencing configurations and toward less expensive, multiple smaller "huddle" rooms for conferencing. Growth in cloud-based conferencing solutions using Skype, Jabber, Microsoft Lync, etc. continues to expand. If the product or service does not support conferencing, then it is likely to add conferencing soon or watch its sales decline.
The continued popularity of BYOD adds more people to the conferencing community, but conferencing rooms are no longer the primary location. Conference participants are using their own devices (smartphones, tablets, laptops, phablets, etc.), as well as a variety of interfaces, including the USB. There is a growing awareness of the importance of microphone and speaker quality and echo cancellation.
The common experience is that the farther you are from a sound source, the lower the sound volume. The loss of sound loudness is covered by the inverse square law, which is a physics principle that the effect of certain forces, such as sound, varies by the inverse square of the distance between the listener and the sound source. For example, a person placed three feet away from a sound source will receive only one ninth ( (1/3)^2, the inverse of 3 squared) as much sound as a person placed one foot from the sound source.
Sound loudness is measured in decibels (dB). Normal conversation at 3 feet (1 meter) is about 60 to 65 dB. A change in power by a factor of 10 corresponds to a 10 dB change in level. A change in power by a factor of two approximately corresponds to a 3 dB change.
90 dB is about twice as loud as 84 dB. 90 dB is four times louder than 70 dB. The father away from the microphone and speaker, the less sound volume (lower dB).
The microphone is the ear of the conferencing equipment. Microphones can pick up sound all around (omni-directional) or they can focus on a particular area, capturing frontal sound and not rear sound.
The diagram to the right is an example of a directional microphone's sensitivity shown in a polar chart, illustrating the pickup pattern of a particular microphone. The green line shows the level of sensitivity relative to the direction of the sound source. This type of microphone separates the desired sound and the unwanted sound.
There will be the walls, floor, and ceiling -- all of which can be reflecting spoken sound. The reflected sounds are forms of noise that can make speech sound degrade. Ceiling microphones may cover a room well, but because much of the sound received by the ceiling microphone is reflected, the sound pickup is poor. The same conditions are true for walls and the floor.
The signal-to-noise ratio (how loud the speaker is vs. the reflected noise) will not be maximized because the signal will be primarily composed of reflected energy. Reflections off the table, the users' bodies, and other surfaces will arrive at the microphone at differing times. Thus, huddle room locations should have surfaces that reflect less sound.
The considerations mentioned are part of the design of audio conferencing. There is noise, both in the huddle room area as well in the equipment itself. The distance from the microphone will seriously affect the overall sound quality transmitted to the people on the other end of the line. Directional microphones placed near the speaker can reduce this problem.
Digital signal processors (DSPs) and their software can minimize the noise while improving the sound quality, but DSP specifications may be hard to understand. Testing different vendor implementations under poor sound conditions will help narrow the final choices.
I have written about the people side of conferencing as well. See the following posts for more about conferencing from that angle: Phases to Pervasive Collaboration, Better Audio Conferences, Collaboration is Not Automatic.
