Face masks and their effects on Speech understanding
According to the government regulations, wearing a face covering/face mask is a mandatory requirement, as they cover the nose and mouth, and are resistant to droplets and stop the spread of the coronavirus. (COVID 19).
Face masks have limitations for individuals with hearing loss and make it difficult for them to understand speech. Choosing the right mask and right amplification can make it easier for individuals with hearing loss.
Various types of face coverings have been used such as medical surgical masks, single use masks, washable cloth masks in different shapes and fabrics, and masks/shields made with transparent plastic.
A study by Ryan et al 2021 looked at how different face masks affect how one hears speech. The image below (from the research paper by Ryan et al 2021) shows how much reduction in speech occurs with different types of face masks.
A summary of the findings of this study are as follows:
- HIGH FREQUENCY REDUCTION: Facemasks cause a mild reduction of the speech signal at 1-4kHz, a moderate reduction at greater than 4kHz
- TYPE OF FABRIC/NUMBER OF LAYERS: The weave of the fabric affects the speech i.e. the tighter the weave, the more the speech is reduced. And the more the layers in the facemask, the more the speech is reduced.
- CLEAR WINDOW MASKS/ SHIELDS: These are helpful as they allow the listener to lip read making it easier to understand speech. However they reduce high frequencies by about 13dB
- BEST MASK? surgical masks and KN95 are best for speech understanding. Masks with clear windows are suitable for those who rely on visual cues for speech understanding. However studies looking at droplet transmission, report that loosely woven face coverings provide poor protection despite enabling better speech understanding.
Are you struggling to hear well and having difficulties understanding speech, why not book an appointment for a hearing test at Golden Ears Audiology Clinic