In intercultural situations, decoders can never be as sure as they are in intracultural situations that they are interpreting signals and messages as originally intended by encoders. This is the result of:

a) cultural differences in the use of all nonverbal channels

Explanation:

Different cultures have different nonverbal and verbal means of communication, so signals sent might be decoded differently by the decoders of cultural background.

The nonverbal sign that means one thing in one culture sometimes means an absolutely different thing in another culture.

This cultural difference may represent the noise, which is anything that may distort the message and it's sending and decoding process. Here, the noise that occurs is cultural noise, or rather semantic and psychological.