clamour
豗 centers on loud, chaotic noise: a clamour or uproar. The single given meaning is narrow, so treat the core idea as a noisy disturbance.
豗 combines 兀 (a raised or prominent shape) with 豕 (pig). The exact historical origin is uncertain, but it may depict a pig making noise or a clamorous scene involving pigs.
Picture a pig (豕) stuck under a high, prominent frame (兀), squealing loudly and creating a clamour.
For カ, imagine the loud clamour of a car horn: car -> カ, and the pig inside the frame is startled by the noise.