Geräuschlokalisierung

Geräuschlokalisierung refers to the ability of an organism to determine the location of a sound source. This is a fundamental sensory process for many animals, including humans, and plays a crucial role in survival, navigation, and social interaction. The primary mechanism for sound localization relies on processing differences in the auditory input received by two ears.

There are two main cues used for sound localization: interaural time differences (ITDs) and interaural level differences (ILDs). ITDs are the slight time delays between a sound arriving at one ear compared to the other. For sounds originating from the sides, this time difference is more pronounced. ILDs are differences in the intensity or loudness of a sound as it reaches each ear. A sound coming from one side will be slightly louder in the ear closer to the source due to the head acting as an acoustic shadow.

These binaural cues are processed in the brainstem, specifically in the superior olivary complex, which contains specialized neurons that are sensitive to both time and level differences. The brain then integrates these signals to create a spatial representation of the sound source. For vertical localization, where ITDs and ILDs are less effective, the shape of the outer ear (the pinna) plays a significant role. The folds and curves of the pinna filter sound waves in a way that creates distinct spectral cues, allowing the brain to distinguish between sounds coming from above or below. While primarily a binaural process, monaural cues and prior knowledge about the environment can also contribute to accurate sound localization.