Purpose: This study evaluates the exposure of call center operators (CCOs) to occupational noise,... more Purpose: This study evaluates the exposure of call center operators (CCOs) to occupational noise, its association with auditory and nonauditory symptoms, and the feasibility of monaural and binaural headsets. Method: We measured the noise exposure sound pressure levels (SPLs) with the microphone-in-real-ear technique and administered a questionnaire on auditory/nonauditory symptoms and headset preference. Results: We assessed 79 CCOs with normal hearing. Overall, 98.7% of the participants reported at least one auditory symptom, and 88.6% reported at least one nonauditory symptom after using the headset. We found significant associations between the headset volume setting and the number of auditory and nonauditory symptoms and between sharp increases in sound level and tinnitus. The microphone-in-real-ear diffuse-field–related SPLs with monaural headsets (85.5 dBA) were significantly higher than those with binaural headsets (83.1 dBA). Binaural headsets were the preference of 84.8% of the subjects. The SPLs of the binaural headsets were significantly lower than those of the monaural headsets in the subjects who preferred the binaural headsets. Conclusions: CCOs with normal hearing reported auditory and nonauditory symptoms, highlighting the need for attention and further investigation. The binaural headsets were preferable, as they were associated with a lower SPL and a higher call quality. Supplemental Material: https://doi.org/10.23641/asha.18361463
Introduction: In a 1754 publication, Discussion plus particulière de diverses manières d’elever d... more Introduction: In a 1754 publication, Discussion plus particulière de diverses manières d’elever de l’eau par le moyen des pompes avec le plus grand avantage (Very detailed explanation of the different methods of raising water through pumps with the greatest effectiveness), Leonhard Euler (1707–1783) made extensive use of the concept of mechanical power in estimates of the power needed to raise waters with piston pumps, by means of natural forces such as human and horse force, running waters, and windmills. Purpose of the study: We aimed to revisit this publication to show to the modern reader Euler’s pioneering approach in providing rational calculations of the power of natural forces needed to drive different machines to raise waters with piston pumps. Methods: After a brief historical review on the use of natural forces to drive machines and the evolution of the concept of mechanical power, the method employed was the examination and an annotated reproduction of the main formulation using Euler’s original notation and ways of scientific writing of the time. Discussion: We address the evolution of hydropower and wind power, particularly for the generation of electricity, and also show that despite of its much lower attractiveness, there have been some attempts in the use of human and animal power in developing countries, particularly in applications that do not require large and constant amounts of power inputs.
Purpose: This study evaluates the exposure of call center operators (CCOs) to occupational noise,... more Purpose: This study evaluates the exposure of call center operators (CCOs) to occupational noise, its association with auditory and nonauditory symptoms, and the feasibility of monaural and binaural headsets. Method: We measured the noise exposure sound pressure levels (SPLs) with the microphone-in-real-ear technique and administered a questionnaire on auditory/nonauditory symptoms and headset preference. Results: We assessed 79 CCOs with normal hearing. Overall, 98.7% of the participants reported at least one auditory symptom, and 88.6% reported at least one nonauditory symptom after using the headset. We found significant associations between the headset volume setting and the number of auditory and nonauditory symptoms and between sharp increases in sound level and tinnitus. The microphone-in-real-ear diffuse-field–related SPLs with monaural headsets (85.5 dBA) were significantly higher than those with binaural headsets (83.1 dBA). Binaural headsets were the preference of 84.8% of the subjects. The SPLs of the binaural headsets were significantly lower than those of the monaural headsets in the subjects who preferred the binaural headsets. Conclusions: CCOs with normal hearing reported auditory and nonauditory symptoms, highlighting the need for attention and further investigation. The binaural headsets were preferable, as they were associated with a lower SPL and a higher call quality. Supplemental Material: https://doi.org/10.23641/asha.18361463
Introduction: In a 1754 publication, Discussion plus particulière de diverses manières d’elever d... more Introduction: In a 1754 publication, Discussion plus particulière de diverses manières d’elever de l’eau par le moyen des pompes avec le plus grand avantage (Very detailed explanation of the different methods of raising water through pumps with the greatest effectiveness), Leonhard Euler (1707–1783) made extensive use of the concept of mechanical power in estimates of the power needed to raise waters with piston pumps, by means of natural forces such as human and horse force, running waters, and windmills. Purpose of the study: We aimed to revisit this publication to show to the modern reader Euler’s pioneering approach in providing rational calculations of the power of natural forces needed to drive different machines to raise waters with piston pumps. Methods: After a brief historical review on the use of natural forces to drive machines and the evolution of the concept of mechanical power, the method employed was the examination and an annotated reproduction of the main formulation using Euler’s original notation and ways of scientific writing of the time. Discussion: We address the evolution of hydropower and wind power, particularly for the generation of electricity, and also show that despite of its much lower attractiveness, there have been some attempts in the use of human and animal power in developing countries, particularly in applications that do not require large and constant amounts of power inputs.
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