FFP3 Respirators and Ears - Effects on Middle Ear Pressure and Hearing

The use of facemasks is one of the key strategies for reducing human to human transmission of SARS-CoV-2. There is a variety of facemasks worn in the clinical environment ranging from simple facemasks to devices such as filtering face piece 3M (FFP3M) respirators which are mandatory for some clinicians performing aerosol generating procedures (AGPs.)

It has been shown that wearing face protective equipment attenuates sound causing decay in speech intelligibility, especially transmission of middle-to-high voice frequencies.It has been shown that wearing surgical masks results in up to 23.3% loss of speech intelligibility in noisy environments with advanced face personal protective equipment such as FFP3M devices, accounting for up to 69.0% reduction of speech intelligibility. A reduction in speech intelligibility leads to reduced understanding which may result in miscommunication thereby compromising patient safety. To date, there have been two critical incidents in our department due to miscommunication attributed to wearing FFP3M respirators.

Anecdotally, clinicians have reported nasal congestion and subjective hearing loss during FFP3M respirator usage and after, especially when they are worn for a prolonged period of time. Clinicians working in theatre may be required to wear these devices for a number of hours when involved with AGPs.

The secondary consequences of wearing FFP3M respirators for prolonged periods of time, especially in a theatre setting require scientific exploration. This study aims to investigate the effect of FFP3M respirators on middle ear pressure and hearing, and the extent to which FFP3M respirators attenuate sound. Investigators believe that a reduction in speech intelligibility is not the only explanation for the perception of hearing loss when using FFP3M respirators. Investigators postulate that a transient dysfunction in the eustachian tube pressure regulating system also contributes to hearing loss.

To test this hypothesis, investigators will measure hearing and middle ear pressure using pure tone audiometry and tympanometry before and during FFP3M usage. Investigators will also use SNOT-22 and ETDQ7 questionnaires which are validated patient reported outcome measures for nasal symptoms and eustachian tube function. Investigators hope that this study provides some understanding of the physiological effects of FFP3M respirators on hearing and sinonasal symptoms and improves our understanding of their impact on clinical practice. There are no current studies looking into the effects of FFP3M respirators on eustachian tube function.