(PP301) Acoustic Analyses of Amplified Stethoscopes: Considerations for Audiologists

Abstract: There continues to be a paucity of practical, acoustic information about stethoscopes for health workers with hearing loss and their audiologist. The purpose of this poster is to share some acoustic analysis research and practical tips that impact decision-making when there are multiple factors to consider, such as stethoscope (conventional vs. amplified), severity and configuration of hearing loss, frequency-response characteristics of hearing devices, coupling with stethoscopes and hearing devices, and target auscultation signals among a diverse field of healthcare workers.

Summary: 

Introduction: Hearing loss affects 466 million people globally including health practitioners, who routinely require using stethoscopes for physical examination (WHO, 2019). Stethoscopes are acoustic devices used to listen to a variety of body sounds that would otherwise be undetected by the unaided ear. Appropriate diagnosis of diseases, such as cardiovascular disease, using a stethoscope depends on the experience and the hearing threshold of health professionals and the acoustic parameters of the stethoscope (Nowak & Nowak, 2018). Currently, no standards (or parameters) exist for measuring and reporting the acoustical characteristics of stethoscopes (Atcherson, Franklin, & Smith-Olinde, 2015), which would be especially useful for health workers with hearing loss and their audiologists. Pasterkamp et al. (1997) stated >20 years ago that “stethoscopes are rarely tested, rated, or compared and are often chosen for their appearance, reputation, and inadequately supported claims of performance” (p. 974), and this currently remains the case. Although stethoscopes provide specifications, consumers must rely on the individual claims made by manufacturers regarding gain (dB) and frequency (Hz). Unfortunately, these claims cannot be assumed to be uniformly distributed across frequencies and directly applied to health workers with hearing loss. 

 

Purpose: To date, there are only a handful of refereed and non-refereed papers describing stethoscope issues with respect to health workers with hearing loss (Fabry, 1993; Jacob et al., 2013; Bankaitis, 2019; Alanazi et al., 2020). Thus, the purpose of this poster is to share some research and practical tips that impact decision-making when there are multiple factors to consider, such as stethoscope (conventional vs. amplified), severity and configuration of hearing loss, frequency-response characteristics of hearing devices, coupling with stethoscopes and hearing devices, and target auscultation signals among a diverse field of healthcare workers.

Methods: Part I - Brief summary of existing literature to identify common themes associating with stethoscope-related issues among healthcare workers and students. Part II - Perform acoustic analyses of a variety of amplified stethoscopes (e.g., Cardionics E-Scope II, ThinkLabs, EKO, etc.) compared to a popular non-amplified stethoscope (e.g., Littmann Classic II S.E.). Acoustic analyses will be performed at low, mid, and high stethoscope volume levels (except for the non-amplified stethoscope) using a 20-20,000 Hz tonal sweep presented through the stethoscope bell/diaphragm; recorded using a Bruel & Kjaer Type 4128C Head and Torso Simulator whose output is amplified via SoundConnect2 amplifier and TASCAM DR-680 digital recorder, and analyzed using acoustics software. Part III - Translate Parts I and II to determine practical considerations for audiologists with respect to unaided and aided ears (e.g., hearing aids and implantable devices).