When engaging in voice communications via an Inmarsat-B or F77 terminal, what procedures are used?

In the context of voice communications using Inmarsat-B or F77 terminals, the correct procedure involves the use of CODECs to digitize the voice signal. CODECs, which stand for coder-decoders, are essential for transforming analog audio signals into digital data and vice versa. This allows for efficient transmission of voice over satellite communications, enabling clearer and more reliable communication over long distances.

The utilization of CODECs is particularly important in maritime communication systems where bandwidth is limited. By digitizing and often compressing the audio signal, CODECs manage the available bandwidth effectively while maintaining an acceptable level of voice quality. This is crucial in environments where clarity and immediacy in communication can be vital for safety and operational efficiency.

The other processes mentioned, such as noise-blanking, compression of the voice signal, and expansion at the receiving terminal, may play a role in specific contexts of voice transmission but do not highlight the primary and necessary function of CODECs in the initial stage of digitizing the voice signal for satellite communication. Thus, focusing on the role of CODECs provides a clear understanding of a fundamental component in the voice communication process for maritime satellite systems.