Free field localisation with a single sound transducer.

Area of Science:

• Auditory perception
• Human factors engineering
• Acoustics

Background:

• Accurate auditory localization is crucial for spatial awareness and situational understanding.
• Protective helmets can potentially alter sound perception and spatial hearing capabilities.
• Understanding these effects is vital for designing effective headgear for various applications.

Purpose of the Study:

• To investigate the impact of different helmet configurations on auditory localization performance.
• To quantify the degradation in sound source localization accuracy caused by specific helmet models.
• To assess the subjective experience of sound perception while wearing active helmets.

Main Methods:

• Auditory localization tasks were conducted in an anechoic chamber using a rotating sound source.
• Three subjects participated, with responses measured to the nearest 10 degrees of azimuth.
• Localization accuracy was assessed under three conditions: no helmet, DH-178 helmet (passive and active modes), and DH-140 helmet (active mode).

Main Results:

• Without helmets, auditory localization was accurate across all azimuths.
• The DH-178 helmet in passive mode narrowed the localization response field.
• Active modes of both DH-178 and DH-140 helmets further degraded localization accuracy, with the DH-140 showing the most significant impact. Sounds were perceived as internal in active modes.

Conclusions:

• Protective helmets, particularly in active modes, significantly impair auditory localization abilities.
• The DH-140 active helmet demonstrated the most substantial degradation of spatial hearing.
• Active helmet use can lead to a perception of sound originating from within the head, impacting spatial awareness.