Far-field Pickup Technology: Clear Audio from Every Corner of the Classroom

Far-field Pickup & Recognition: Why Standard Devices Fail in Lecture Halls

In lecture halls, recording devices face extreme acoustic challenges. Sound energy decreases with the square of distance. Sitting in the back row (10–20 meters away), the captured audio may have less than 5% of the energy of the front row. Wall reflections generate interfering waves, making recordings highly muffled and difficult to capture accurately with ordinary devices.

Capsu’s Cloud-based Software Beamforming

1. Weak Signal Gain Compensation

The algorithm non-linearly amplifies weak human voice frequencies, specifically in the 300Hz–3400Hz range, avoiding amplification of background noise and ensuring clarity.

2. Software Beamforming

By calculating slight time differences between multiple audio paths, AI simulates a “virtual funnel” pointing at the lecturer, suppressing side noises from students, such as air conditioning or typing.

3. High-frequency Consonant Reconstruction

Long-distance recordings lose high-frequency fricatives (S, F, Th). AI uses deep learning to predict these sounds, correcting words that might otherwise be misheard or misspelled.

Conclusion: Eliminating Positional Disadvantages

Far-field recognition technology removes the physical limitations of seating. No matter where you sit, AI restores front-row audio quality, making classroom learning equally effective for everyone.