Noise Reduction in Teleconferencing Rooms
Office Noise Reduction
Sound Masking for Offices
Meeting Rooms Sound Control Solutions
Acoustical Design for Office Spaces
Have you ever spoken on the telephone to someone who is using a speakerphone? Chances are that the quality of the signal was not good. It may have sounded as though they were speaking through a pipe or in a cave – that “tin can” effect.
Usually it’s not the phone, it’s the room.
The microphones in speakerphones are very sensitive; more sensitive than our ears. They pick up not only the first incidence of sound, but also the many successive reflections of that sound as it bounces from the hard surfaces within the room. You may not hear it, but the microphones pick it up. The result is distortion.
This is a smaller scale version of the effect of announcements we frequently hear in a large space such as an arena, railroad station or airline terminal. You can hear, but it’s very difficult to understand. As one word is spoken (usually amplified and delivered through a loud speaker system) it reflects from the various surfaces in the space and we hear it again and again. Although at diminishing volume, it overlaps and interferes with the next word or syllable. Under extreme conditions, you hear much and understand little.
In a smaller venue, the distortion is hardly perceivable to the people within the room if at all. Their ears are not that sensitive. The microphones, however, do pick up those reflections and record and/or transmit them. That’s why the audio quality on your home video tape may not be what you heard when you recorded it. Again, it is not the equipment, but the room.
In a video/conference room this distortion is most always annoying to the listeners at the remote receiving location and may interfere with understanding. A reverberation time of less than 0.5 seconds is desirable, whereas times in excess of one second are typical of untreated rooms.
To correct this, acoustical (sound absorbing) treatments are added to those surfaces. The walls are the most important surfaces to be treated as they permit multiple (more than one bounce) reflections. The application of acoustical panels above chair-rail height usually corrects the problem. For rooms with hard ceiling surfaces flush mounted panels are usually required. The quantity of those panels, their performance (NRC) and their placement is an important design consideration.