Abstract
Background: Ambient noise presents a persistent challenge to the accuracy of audiometric evaluations, particularly in settings outside traditional sound-attenuating booths. The Kuduwave audiometer is engineered to address this challenge through a sophisticated real-time ambient noise monitoring system.
Objective: This white paper elucidates the interpretation of the Kuduwave’s “Noise in ear canal (External mic) dB HL” (SPHLin-ear – Sound Pressure Hearing Level in the ear canal) metric, a critical indicator of noise levels within the patient’s ear canal, referenced to audiometric zero. It details an advanced 4-step calculation for this metric, incorporating a crucial internal +3dB Sound Pressure Level (SPL) recording safety offset and Maximum Permissible Ambient Noise Level (MPANL)-standard-specific correction factor. A key aspect is that Kuduwave-specific MPANLs, used for deriving these correction factors, are now sourced from the definitive GeoAxon guide: “Establishing Maximum Permissible Ambient Noise Levels for the Kuduwave Audiometer: A Guide for Clinical, Research, and Proposed Unified Global Applications” This paper aims to detail the derivation of corresponding “Noise in ear canal (External mic) dB HL” correction factors for ANSI S3.1, ISO 8253-1, and SANS 10182 standards, for both foam and silicone eartips.
Methods: The methodology involves applying the Kuduwave’s 4-step “Noise in ear canal (External mic) dB HL” calculation framework, which includes the internal +3dB SPL offset. MPANL-standard-specific correction factors are derived by utilizing the Kuduwave MPANLs sourced from the aforementioned external GeoAxon guide. These derivations are performed for ANSI S3.1, ISO 8253-1, and SANS 10182 standards, considering both foam and silicone eartip configurations.
Results: The derived “Noise in ear canal (External mic) dB HL” correction factors are presented in comprehensive lookup tables. Furthermore, this paper explains the Kuduwave’s enhanced real-time noise display features, its peak noise monitoring methodology, and introduces the concept of “Minimum Plateau Threshold” annotation.
Conclusion: The principles and calculations detailed herein are of significant consequence for advancing boothless audiometry. They serve to enhance diagnostic confidence and expand the reach of reliable hearing assessments, positioning the Kuduwave system as a pivotal tool in modern audiology.