Everyday speech communication usually occurs under partial masking conditions

Evidence

This means that partial masking produces a loudness function that is comparable to that described by audiologists as recruitment. The effect illustrated in Fig. 8.10 seems reasonable and understandable from what we have learned in everyday conditions where communication very often takes place under partially masked conditions. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1216