What are the reasons for the noise generated by conference audio?

Reasons for noise in conference audio

(1) Circuit noise inside the device

Audio equipment has an indicator - signal-to-noise ratio. Due to the electrical noise generated by internal electronic components, when a device works alone, it can meet the required indicators, but when multiple devices are cascaded, the noise will accumulate and increase.

In practical applications, some low-end civilian audio equipment will have a lot of AC noise due to poor internal power supply filtering, which sometimes causes serious noise in the audio system.

(2) Ground loop noise

In the audio system, the entire system must be well grounded, and the grounding resistance is required to be less than 4 ohms. Otherwise, the induced charges generated by various radiation and electromagnetic induction in the equipment in the audio system will not be able to flow into the ground, thus forming a noise voltage superimposed on the audio signal.

If there is a ground potential difference between the ground wires of different devices due to different ground resistances, or if there is a loop in the internal ground of the system, ground noise will be caused. Noise may also be generated when two different audio systems are interconnected, and the noise is caused by the direct connection of the ground wires of the two systems.

Reasons for noise in conference room audio

1. Strong reflected sound enters the microphone and is amplified by the system to produce positive feedback, causing howling.

2. The speaker installation position is not good. A pair of speakers are placed at the two corners of the conference room. The sound they emit is at the same height as the microphone, so the direct sound or the sound reflected by the wall is easier to enter the microphone, and howling is inevitable.

3. The speaker is too far away from the microphone, resulting in a weak voice. However, increasing the volume will also cause howling due to the limitation of sound transmission gain.

4. The system has no electronic acoustic feedback suppressor and is prone to howling.

5. The meeting room is small and the sound waves do not diffuse well.