How does Broadbent's filter theory explain the process of information selection?

Broadbent's filter theory, also known as the early selection theory, explains information selection as a process where unattended information is filtered out early in the perceptual processing stage. According to this theory, sensory information enters the system and is briefly held in a sensory buffer. Then, a selective filter allows only certain information to pass through for further processing, based on physical characteristics such as location, pitch, or intensity. The unattended information is assumed to be blocked or filtered out at this early stage, preventing it from reaching higher-level processing stages such as semantic analysis or meaning extraction. For example, in a cocktail party scenario, you might focus your attention on the person you are talking to, filtering out the other conversations based on their location or voice characteristics. The unattended conversations are blocked from further processing, so you are not consciously aware of their content. Broadbent's filter theory suggests that our attentional system has a limited capacity, and the filter serves as a bottleneck to prevent overload. However, the theory has been criticized for not fully accounting for instances where unattended information does influence behavior, suggesting that some semantic processing can occur even for filtered information.