The noise generated by the audio and video capture card during the acquisition process may be caused by the following main reasons:
1. Hardware quality issues: Poor hardware quality of the capture card itself, such as unreasonable circuit board design, aging or damage of components, may cause noise during the acquisition process.
2. Electromagnetic interference (EMI): External electromagnetic field interference, such as nearby electrical equipment, power lines or wireless signals, may generate additional noise on the capture card.
3. Grounding issues: Improper grounding or grounding loops may cause noise in the audio channel, especially in professional audio applications.
4. Signal source issues: If the input signal itself contains noise, the signal collected by the capture card will also carry this noise.
5. Cables and connections: Using poor quality audio or video cables, or loose connections, may cause signal attenuation and increased noise.
6. Driver or software issues: If there are bugs in the capture card driver or related software, it may also cause abnormal noise in the captured signal.
7. Pickup or microphone quality: When capturing audio, if the microphone or pickup used is of low quality, they may introduce additional ambient noise.
8. Echo and reverberation: In an enclosed space, sound reflections may produce echoes, especially without proper sound-absorbing materials.
9. Improper signal gain setting: If the signal gain is set too high, background noise may be amplified.
10. Power fluctuations: Unstable or unclean power may also affect the performance of the capture card and cause noise.
To reduce or eliminate these noises, you can try the following solutions:
• Use high-quality capture cards and accessories.
• Make sure all devices are properly grounded to avoid ground loops.
• Use shielded audio and video cables to ensure a secure connection.
• Check and update the capture card driver.
• Stay away from potential sources of electromagnetic interference as much as possible.
• Adjust the gain setting to avoid excessive gain.
• Use professional audio editing software for post-noise reduction.
• Take appropriate sound insulation measures in the audio capture environment.
• Regularly maintain and clean equipment to ensure the hardware is in good condition.
