Spatial audiometry: detection of spondaic words in noise

Area of Science:

• Audiology
• Psychoacoustics
• Speech Perception

Background:

• Standardized spatial audiometric tests require careful selection of stimuli and test conditions.
• Understanding binaural detection thresholds (BDTs) in the presence of noise is crucial for spatial hearing assessment.

Purpose of the Study:

• To investigate the influence of angular separation and target stimuli on binaural detection thresholds (BDTs).
• To compare the effectiveness of speech spectrum noise (SSN) and multitalker noise (MTN) as maskers in spatial audiometry.
• To provide recommendations for developing a clinical test of spatial detection.

Main Methods:

• Three experiments were conducted measuring BDTs for target signals at various azimuths (0-315 degrees) with maskers at different locations.
• Spondaic words from the CID W-1 list were used as target stimuli.
• Bekesy tracking was employed to measure BDTs in normal-hearing listeners using SSN or MTN as maskers.

Main Results:

• BDTs were significantly affected by the angular separation between target and noise sources.
• The choice of spondaic words influenced BDTs, with variations up to 13 dB for a given separation.
• Masker type (SSN vs. MTN) had a minimal effect (<3 dB) on BDTs, indicating comparable masking properties for spatial detection.

Conclusions:

• A single spondaic word is suitable for spatial audiometric detection tests.
• SSN and MTN are comparable as masking noises for spatial detection tasks.
• A clinical spatial detection test should utilize SSN and a single spondaic word, measuring detection across several signal/noise configurations.