What is the process called when sounds change according to the company they keep?

Assimilation refers to the process where sounds become more similar to adjacent sounds in their environment. This phenomenon occurs frequently in spoken language as a way to facilitate smoother and quicker speech. For example, in rapid speech, the phrase "ten bikes" can be pronounced more like "tem bikes," where the "n" sound changes to a "m" sound because of the following bilabial "b" sound. This process illustrates how sounds adapt to fit more comfortably with neighboring sounds, ultimately helping with the fluidity of speech.

Dissimilation, on the other hand, involves sounds becoming less similar, while sound reduction relates to a decrease in the articulatory effort or clarity of sounds. Semantic shift, conversely, deals with changes in meaning of words over time. Understanding assimilation highlights the dynamic nature of phonetics and emphasizes how language evolves in casual use.