Partially masked sounds have a reduced loudness range in both time and spectrum

Evidence

Besides loudness in quiet, we often hear the loudness of partially masked sounds. This loudness occurs when a masking sound is heard in addition to the sound in question. The remaining loudness ranges between a loudness of “zero”, which corresponds to the masked threshold, and the loudness of the partially masked sound is mostly much smaller than the loudness range available for unmasked sound. Partial masking can appear not only with simultaneously presented maskers but also with temporary shifted maskers. Thus the effects of partially masked loudness are both spectral and temporal. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1168

Categorization

• DEFINE: Introduces partial masking as a core concept distinguishing masked from unmasked loudness.
• XREF: Connects to masking theory and critical bands from earlier chapters, and foreshadows temporal/simultaneous masking details.