The Negative Pressure Face Shield confines the bioaerosol produced by singing to mitigate spread of COVID demonstrated below with modifications to the unamplified acoustic performance identified with microphone and earbuds/headphones further below.

See how to set up the NPFS: Negative Pressure Face Shield (NPFS) for Transnasal Laryngoscopy to Mitigate Dispersion of Bioaerosol in COVID Era 

see also: Bioaerosols, microdroplets, droplets and COVID-19; Wind Instrument Aerosol in Covid Era - COVID-19 and horns, trumpets, trombones, euphoniums, tubas, recorders, flutes, oboes, clarinets, saxophones and bassoons

University of Iowa School of Music COVID-19 Policies: https://music.uiowa.edu/school-music-covid-19-policies (last update 8.14.20)

Music video demonstrating cleaning and setup: Dream a Little Dream of Me with the NPFS - Safe Singing in the COVID Era