Acoustic analysis and self assessment of speech with face masks and shields

Tijekom pandemije koronavirusa suočeni smo s novim načinom života koji, između ostaloga, podrazumijeva i nošenje pokrivala za lice. Svakodnevno nošenje maske i/ili vizira otežava disanje i govor, što je posebice izraženo u vokalno zahtjevnim profesijama. Prema tome, u ovome su radu ispitani utjecaji maske i vizira na akustička obilježja govora te samoprocjena glasa kod nastavnika prije i tijekom pandemije. Rezultati akustičke analize pokazali su da je govor s kirurškom maskom najsličniji govoru bez pokrivala, a da je pri nošenju vizira zvuk u najvećoj mjeri intenzitetski osiromašen. Područje slabljenja govornoga zvuka započinje u spektralnome području iznad 1 kHz, a najveće je oko 4 kHz. Prilikom nošenja različitih pokrivala za lice utvrđena su uglavnom sniženja F0 i to kod medicinske maske u rasponu od 0,5 Hz do 5,93 Hz, kod platnene maske od 0,3 Hz do 6,06 Hz, a pri nošenju vizira od 0,6 Hz do 4,6 Hz. Intenzitetski su padovi pri nošenju medicinske maske iznosili od 0,06 dB do 7,05 dB, pri nošenju platnene maske od 0,15 dB do 3,3 dB, dok se pri nošenju vizira raspon pada protezao od 0,45 dB do 5,66 dB. Analizom anketne samoprocjene glasa kod nastavnika utvrđene su učestalije i teže vokalne poteškoće tijekom pandemije te nedovoljno znanje o vježbama za očuvanje, zaštitu i snaženje glasa.During coronavirus pandemic we have been faced with a new lifestyle, which, among many other changes, includes wearing face coverings. Everyday use of face masks and/or face shields makes breathing and speech more difficult. These difficulties are more prominent in vocaly challenging professions, such as teaching. Therefore, the acoustical impact of different face coverings (surgical mask, cloth mask, face shield) on speech has been studied using the following parameters: fundamental frequency, intensity and long-term average speech spectrum (LTASS). Also, a self assessment questionnaire about voice, voice habits and problems has been filled by the teachers. Acoustic analysis showed that speech with surgical face mask resembles the speech without face coverings the most. On the other hand, speech with face shield has shown the greatest intensity loss. Speech sound loss has been detected in the frequency region around 1 kHz, but the greatest loss has been present around 4 kHz. While speaking with different face coverings, the lowering of fundamental frequency has been noticed in most of the speech samples. Speech with face surgical mask showed F0 lowering from 0.5 Hz to 5.93 Hz while speech with face cloth mask F0 showed lowering from 0.3 Hz to 6.06 Hz. Speech with face shield showed more consisted F0 lowering, ranging from 0.6 Hz to 4.6 Hz. Intensity losses have been detected in all speech conditions: speech with surgical (from 0.06 dB to 7.05 dB) and cloth masks (from 0.15 dB to 3.3 dB) as well as in speech with face shield (from 0.45 dB to 5.66 dB). The self assessment results from VHI before and during coronavirus pandemic showed more frequent and heavier voice problems during pandemic in comparison to period before pandemic. Also, none of the participants were aware of speech and voice exercises for voice care, which would be useful in their profession in general and especially during the pandemic