Just noticeable differences of spatial cues in echoic and anechoic acoustical environments

Area of Science:

• Acoustics
• Psychoacoustics
• Auditory perception

Background:

• Perceptual limits for binaural cue changes define spatial impression boundaries.
• Understanding these limits is crucial for designing immersive audio experiences.

Purpose of the Study:

• To determine just noticeable differences (JNDs) for ITDs, ILDs, and IACC.
• To investigate the impact of reverberation on the perception of these binaural cues.

Main Methods:

• Measured JNDs for ITDs and ILDs in the early part of binaural room impulse responses (BRIRs).
• Measured JNDs for interaural cross-correlation (IACC) in both early and diffuse parts of BRIRs.
• Assessed localization accuracy in anechoic and reverberant environments.

Main Results:

• Interaural time delays (ITDs) provide high localization accuracy only in anechoic settings.
• Interaural level differences (ILDs) demonstrate greater robustness against reverberation.
• Listeners are largely insensitive to IACC changes, with only those approaching one being detectable.

Conclusions:

• ILDs are more critical than ITDs for robust spatial localization in realistic (reverberant) environments.
• The perception of spatial impression is strongly influenced by the interplay between different binaural cues and environmental acoustics.
• Further research into IACC perception may be needed to understand its role in spatial impression.