🥸intro to psychology review

key term - Interaural Level Difference

Definition

Interaural level difference (ILD) is the difference in sound intensity or loudness between the two ears. It is one of the primary cues the auditory system uses to localize the direction of a sound source in the horizontal plane.

5 Must Know Facts For Your Next Test

  1. Interaural level difference is caused by the head acting as an acoustic shadow, attenuating the sound intensity at the ear that is farther from the sound source.
  2. The magnitude of the ILD depends on the frequency of the sound, with higher frequencies experiencing greater attenuation due to the head's shadowing effect.
  3. ILD cues are most useful for localizing sound sources in the horizontal plane, particularly at frequencies above 1500 Hz, where the head's size is comparable to the wavelength of the sound.
  4. The auditory system combines ILD information with other spatial cues, such as interaural time difference and spectral cues, to accurately determine the direction of a sound source.
  5. Disruptions in binaural hearing, such as unilateral hearing loss, can impair an individual's ability to use ILD cues effectively for sound localization.

Review Questions

  • Explain how the head's acoustic shadowing effect contributes to interaural level difference.
    • The head acts as an acoustic shadow, attenuating the sound intensity at the ear that is farther from the sound source. This difference in sound level between the two ears is known as the interaural level difference (ILD). The magnitude of the ILD depends on the frequency of the sound, with higher frequencies experiencing greater attenuation due to the head's shadowing effect. This is because at higher frequencies, the wavelength of the sound is comparable to the size of the head, making the shadowing effect more pronounced.
  • Describe the role of interaural level difference in sound localization and binaural hearing.
    • Interaural level difference (ILD) is one of the primary cues the auditory system uses to localize the direction of a sound source in the horizontal plane. By comparing the differences in sound intensity between the two ears, the brain can determine the approximate direction of the sound source. ILD cues are most useful at frequencies above 1500 Hz, where the head's size is comparable to the wavelength of the sound. The auditory system combines ILD information with other spatial cues, such as interaural time difference and spectral cues, to accurately determine the direction of a sound source, a process known as binaural hearing. Disruptions in binaural hearing, such as unilateral hearing loss, can impair an individual's ability to use ILD cues effectively for sound localization.
  • Analyze how interaural level difference and interaural time difference work together to enable accurate sound localization.
    • Interaural level difference (ILD) and interaural time difference (ITD) are the two primary binaural cues the auditory system uses to localize sound sources. ILD provides information about the direction of a sound source in the horizontal plane, while ITD provides information about the direction in the vertical plane and front-back axis. The auditory system combines these two cues, along with spectral cues, to triangulate the precise location of a sound source. ILD is more useful at higher frequencies, where the head's shadowing effect is more pronounced, while ITD is more useful at lower frequencies, where the time difference between the two ears is more detectable. By integrating these complementary binaural cues, the brain can accurately determine the direction and distance of a sound, enabling precise sound localization and spatial awareness.

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