CHALLENGE #1: INCONSISTENT AUDIO LEVELS AND CLARITY THROUGHOUT THE ROOM
When the audio quality changes as presenters move about the room, they learn to stay in the best location throughout their presentation so they are not interrupted by remote attendees saying they cannot hear. However, staying in place limits the presenter’s ability to engage with in-room participants. This inconsistent audio experience is often created by misjudging the mic coverage in a room. Too many mics can cause processing artifacts and increased reverberation, which impacts speech intelligibility.
Solution: CONDUCT AN ACOUSTICAL ANALYSIS TO DETERMINE APPROPRIATE MIC SELECTION AND PLACEMENT
An analysis should consider room dimensions, materials, furnishings and overall acoustical properties to determine the mic requirements, including pick-up range, type, quantity and placement. Individual ceiling mics -instead of a ceiling array mic- allows mics to be placed at approximately the same distance from all in-room participants, optimizing the audio experience for remote participants.
CHALLENGE #2: UNWANTED NOISE AND REVERBERATION
Air flow and vibrations from HVAC systems can be a significant source of noise, when using ceiling mics. Other sources of noise include side conversations, tapping on the table or keyboard, and hard surfaces, which reflect sound. When these noises are amplified through the audio system, they can not only distract far-end listeners, but are often loud enough to compete with the presenter’s voice audio. Too much transmitted noise results in unintelligible speech.
Solution: USE MIC PLACEMENT AND DSP CONFIGURATION TO MINIMIZE THESE ISSUES
The distance between the ceiling mics and the table surface (where much of the participant noise is generated) gives ceiling mics an advantage over table mics. To mitigate the effects of HVAC systems, ceiling mics should be located where the mic elements are not in the direct path of the HVAC vent air flow. In addition, using individual ceiling mics instead of ceiling array mics allows more flexibility when determining optimum placement. Beyond strategic mic placement, there are DSP settings that help reduce the effects of noise and reverberation. Most DSP mixers provide noise suppression and two mic controls.
CHALLENGE #3: FLEXIBLE ROOM DESIGNS
Some presenters enjoy roaming the room when speaking while others want a circle configuration instead of rows. Participants may need to move to the front of the room to demonstrate on the whiteboard or share. However, audio systems are typically designed to provide optimal voice pickup based on the original or fixed seating arrangement. Once the room configuration changes, the audio system is unable to effectively accommodate their needs.
Solution: USE CEILING MICS FOR CONSISTENT COVERAGE
To accommodate a mobile, flexible room, consider using ceiling mics that can be strategically placed to evenly cover the entire room—regardless of how the room is configured on any day. Ceiling mics offer better room coverage than table mics, allowing participants to walk around and face away from the desks or table and still be heard evenly.
CHALLENGE #4: UNWIELDY CABLES
The use of table mics often requires running cabling across the floor and under/through tables and desks to connect and power the system. These exposed cables look bad, can be a tripping hazard, are difficult to manage, and disconnect easily. Should the room configuration change, rerouting cables can be time consuming. To address cable issues, some designers rely on wireless mics. While this strategy helps reduce cables, it creates new problems, including higher maintenance due to charging stations and inventory management.
Solution: USE CEILING MICS TO IMPROVE ROOM AESTHETICALLY
Ceiling mics reduce visible cables and are discrete enough not to affect room aesthetics. Recent technological advancements and improvements in
mic design makes the quality of ceiling mic equals and often exceeds tabletop mic quality in many environments.
Even if a room design follows best practices, it’s important to test the system to ensure comfortable audio levels and room coverage. Here are a few pointers on conducting an effective test:
- Listen from a remote location to a person talking in the room.
- Ask that person to move around the room while talking at the same level. This should be a “blind” exercise focused only on the audio.
- Test while the HVAC system is running to determine if it creates any noise interference.
Modern distance learning classrooms and training rooms are flexible in how they are used, and this means audio systems need to be flexible as well. When the four audio issues discussed in this guide are solved, participants can enjoy clear, reliable audio that enables them to learn and engage. Every type of mic has an ideal use case. However, in a classroom or training setting, table mics present challenges as:
- More obtrusive than ceiling mics, creating a visual distraction for learners.
- Create a cluttered classroom environment due to the need to run cables throughout the room.
- Lack flexibility for participants to move around the room since table mics require the speaker to be seated or standing directly in front of the mic at all times.
- More likely to pick upside conversations or tabletop noises such as typing, shuffling of papers, or tapping due to their close proximity to participants.