Purpose: This study aimed to clarify the relationship between use of a face shield and vocalization methods under the wearing of a surgical mask through a subjective evaluation and assessment of sound pressure level.

Methods: Participants comprised 11 undergraduate nursing students in Tokyo, who played the role of nurses. They were asked to vocalize specified sentences in both clear and standard voices, and their voices with and without a face shield were recorded with a digital voice recorder. One participant assumed the patient’s role and was asked to evaluate the audibility of the four different voices of participants in the nurse’s role. Univariate analysis was used, and speech was graphed for sound pressure level using the acoustic analysis software Praat’s Long-term Average Spectrum.

Results: The standard speech vocalization with a face shield (p = 0.021) or without a face shield (p = 0.005) was significantly easier to hear than the clear speech with a face shield. The sound pressure level was similar in the frequency range of 0–2,000 Hz for a large percentage of people with and without a face shield.

Conclusions: It is necessary to use indices other than sound pressure level to clarify the differences in speech depending on whether the face shield is worn and the method of speech vocalization.