Effects of noise on speech prosody

Hrup je eden izmed vodilnih okoljskih dejavnikov, ki vplivajo na pojav fizičnih ali mentalnih bolezni ter znižujejo kakovost življenja prebivalstva. Je tudi pomemben javnozdravstveni problem, saj izpostavljenost prekomernim ravnem hrupa vodi do nastanka poškodb slušnega sistema, kognitivnih motenj, motenj spanja, razdražljivosti in vrste drugih težav, ki negativno vplivajo na človekovo počutje in zdravje. Več kot polovica evropske populacije je vsakodnevno obremenjena s čezmernimi ravnmi hrupa, ki presegajo zakonsko dovoljene vrednosti. Izpostavljenost hrupu vpliva na celotno človekovo delovanje, tako na duševno sfero kot tudi na avtonomno živčevje in endokrini sistem. Hrupu so izpostavljeni predvsem zaposleni v transportnih panogah, industriji in predelovalnih obratih, pa tudi zaposleni v storitvenih dejavnostih, kot so: izobraževanje, zdravstveno varstvo, gostinstvo ipd. Zaradi razvoja in širjenja transporta in industrije se je hrupu skoraj nemogoče izogniti, lahko pa se pred njim vsaj delno zaščitimo, zato je ozaveščanje o negativnih vplivih hrupa na zdravje ter uvajanje smernic za zaščito pred hrupom nujno potrebno. Hrup ima pomemben vpliv tudi na govor in komunikacijo, saj pomembno zmanjšuje sposobnost avditivne kontrole govora, hkrati pa je pod vplivom hrupa zmanjšana tudi razumljivost sporočila. Govorec vlaga več truda v komunikacijo pod vplivom hrupa z namenom ohranjanja avditivne kontrole in razumljivosti govora, zato svoj govor akustično in časovno modificira, kar lahko vpliva na nastanek poškodb govornega organa, poleg tega pa modificiran govor vpliva na poslušalčevo razumevanje sporočila, kar zmanjšuje uspešnost komunikacije. V magistrskem delu je bila izvedena primerjava prozodičnih prvin govora (govorne jakosti, hitrosti artikulacije in govora, tonskega poteka v besedi in stavku ter višine osnovnega tona) štirinajstih bralcev med branjem petih besedil v sedmih različnih akustičnih situacijah (v tišini, pod vplivom cestnega in govornega hrupa na nivoju jakosti 60 dB, pod vplivom cestnega in govornega hrupa z nivojem jakosti 80 dB ter pod vplivom cestnega in govornega hrupa z nivojem jakosti 80 dB, predvajanega z zvočnikom). Poleg tega je bilo preverjeno, katera vrsta in nivo jakosti hrupa sta najbolj moteča za bralce. Bralci so bili med branjem besedil snemani, zvočni posnetki branja pa so bili nato obdelani in analizirani v programu za fonetično analizo govora Praat. Ugotovljeno je bilo, da vrsta in nivo jakosti hrupa vplivata na jakostno strukturo govora, saj se govorna jakost zvišuje skladno z zvišanjem nivoja jakosti hrupa. Vrsta branega besedila na jakostne spremembe govora ni imela vpliva. Hitrost govora in artikulacije sta se pomembno spreminjali glede na vrsto branega besedila, akustična situacija pa na hitrost ni imela pomembnega vpliva. Bralci so umetnostna besedila brali počasneje, najmanjšo hitrost govora in artikulacije so dosegali med branjem pesmi. Hrup in vrsta besedila nista imela pomembnega vpliva na spreminjanje povprečnega laringalnega tona pri vseh bralcih, vendar so bile kljub temu ugotovljene spremembe pri vsakem posameznem bralcu. Tonski potek v besedi se je pod vplivom hrupa spreminjal predvsem pri manj pogosto rabljenih besedah, najpogosteje so se spremembe pojavile med prvim uvajanjem višjega nivoja jakosti hrupa. Stavčna intonacija se je v posameznih stavkih spreminjala v povezavi z okoliškimi stavki in celotnim besedilom, tudi tu so bile spremembe najpogostejše med prvim branjem pod vplivom določenega nivoja jakosti hrupa. Po mnenju bralcev je bil tako za branje kot poslušanje najbolj moteč govorni hrup z nivojem jakosti 80 dB, predvsem zaradi informacijsko maskirajočega učinka. Ugotovitve glede spreminjanja prozodičnih prvin govora pod vplivom hrupa so pokazale, da je hrup pomemben dejavnik, ki negativno vpliva na govorčevo sposobnost lastne kontrole govora, vendar se njegov vpliv med govorci individualno razlikuje. Pomembno je zavedanje o negativnih učinkih hrupa na govorne spremembe ter posameznikovo prilagajanje govora v hrupnih situacijah, saj lahko na ta način govorci, ki so vsakodnevno izpostavljeni komunikaciji v hrupnem okolju, ohranjajo uspešnost komunikacije s sogovorci ter zmanjšajo možnost pojava poškodb govornega aparata zaradi glasnega govora pod vplivom hrupa.Noise is one of the leading environmental factors that affect the onset of physical or mental illness and reduce the quality of life of a population. It is also a major public health problem, as exposure to excessive noise levels leads to damage to the hearing system, cognitive impairment, sleep disorders, irritability, and a variety of other problems that negatively affect human well-being and health. Exposure to noise affects the entire human function, both the mental sphere and the autonomic nervous system and endocrine system. Employees in the transport industries, industry and production are mostly exposed to the noise, however it also affects employees in the service industries such as: education, healthcare, catering, etc. Due to the development and expansion of transport and industry, it is almost impossible to avoid noise, but we can partially protect ourselves from its harmful effects, therefore raising awareness of the negative effects of noise on health and the introduction of noise protection guidelines is essential. Noise also has a significant impact on speech and communication, as it significantly reduces the speaker’s ability of auditory speech control, and also reduces the intelligibility of the message. The speaker invests more effort into noise-induced communication to maintain auditory control and intelligibility of speech, so he modifies his speech acoustically and temporally, which can encourage the occurrence of damage to the vocal cords, and in addition, modified speech affects the listener\u27s understanding of the message, which reduces communication performance. The master\u27s thesis compared prosodic elements of speech (speech loudness, articulation and speech rate, accent, intonation and voice pitch) of fourteen readers while reading five texts in seven different acoustic situations (in silence, under the influence of road and speech noise at 60 dB level, influenced by road and voice noise at 80 dB level and influenced by road and voice noise at 80 dB played with the loudspeaker). In addition, it was tested which type and noise level were most disturbing to the readers. The readers were recorded while reading texts, and audio readings were then processed and analysed in the Praat (program for phonetic analysis of speech). The type and level of the noise have been found to influence the loudness of the speech, since the loudness of the speech increases with the increase of the noise level. The type of read text had no effect on the speech loudness changes. Speech and articulation rate varied significantly depending on the type of text being read, however the acoustic situation had no significant effect on speech rate. Readers were reading literary texts more slowly, with the lowest speech and articulation rate achieved while reading a poem. Noise and text type did not have a significant effect on altering average laryngeal tone in all readers, but changes were observed in each individual reader. The tone of the word under the influence of noise changed especially in less commonly used words, the most frequent changes occurring during the first introduction of a higher noise level. The sentence intonation varied in individual sentences in relation to the surrounding sentences and the whole text, even here changes were most frequent during the first reading under the influence of a certain level of noise. According to the readers, both reading and listening were the most disturbed by speech noise at 80 dB level, mainly due to the information-masking effect. Findings regarding the change of prosodic elements of speech under the influence of noise have shown that noise is an important factor that negatively affects the speaker\u27s ability to control his own speech, but its influence varies between speakers individually. Awareness of the negative effects of noise on speech and the individual\u27s adaptation of speech in noisy situations is important, since speakers who are daily exposed to communication in a noisy environment can maintain the effectiveness of communication with their interlocutors and reduce the possibility of damage to the speech organs due to loud speech in noisy conditions