تاثیر نویز همهمه بر بازشناسی واکه‌های زبان فارسی در دو دهۀ چهارم و پنجم زندگی

ارتباطات کلامی روزمره تقریباً هیچ‌گاه در سکوت رخ نمی‌دهند. نویز همهمه به منزلۀ عاملی مداخله‌گر می‌تواند به ایجاد اختلالات در درک گفتار منجر شود. واکه‌ها هستۀ هجا‌ها و کلمات هستند و خطاهای واکه‌ای می‌توانند به ایجاد اختلال در فرایند درک گفتار منجر شوند. بنابراین، مطالعۀ حاضر به بررسی تاثیرات سن، نسبت سیگنال به نویز، جنسیت و سطح تحصیلات بر بازشناسی واکه‌های زبان فارسی در دو دهۀ چهارم و پنجم زندگی پرداخت. پژوهش مشاهده‌ای مقطعی حاضر بر روی 60 فرد بزرگ سال دارای شنوایی هنجار در محدودۀ سنی 30 تا 49 سال (با میانگین و انحراف معیار 6.23 ± 38.88 سال) از بین نمونه‌های در دسترس انجام شد. پس از انجام ارزیابی‌های شنوایی و گفتاری، بازشناسی واکه‌های زبان فارسی در حضور نویز همهمه و در نسبت‌های سیگنال به نویز صفر، 5 و10 بررسی شد. مقایسۀ امتیاز بازشناسی شش واکۀ زبان فارسی در هر سه نسبت سیگنال به نویز تفاوت معنی‌داری را نشان داد (0.001=p). همچنین، مقایسۀ امتیاز بازشناسی واکه‌ها در سه نسبت‌ سیگنال به نویز در دو محدودۀ سنی 30 تا 39 سال و 40 تا 49 سال معنی‌دار بود (0.001=p)؛ اما تفاوت معناداری با جنسیت (0.991=p) و سطح تحصیلات (0.282=p) افراد یافت نشد. همچنین، در سه نسبت سیگنال به نویز صفر، 5 و 10 امتیاز بازشناسی واکه‌های پیشین بهتر از واکه‌های پسین بود. پژوهش حاضر نشان داد که با افزایش سن و کاهش نسبت سیگنال به نویز میانگین امتیاز بازشناسی واکه‌ها در حضور نویز همهمه به طور قابل توجهی کاهش می‌یابد.

The Effects of Babble Noise on the Recognition of Persian Vowels in the Fourth and Fifth Decades of Life.

Routine verbal communication almost never occurs in quiet. Speech perception disorder in noise is one of the most common complaints of people of all ages. In our living environment, there are different types of background noise that have different masking effects. In general, verbal noises have more signal target masking. Babble noise as an interfering factor can lead to speech perception disorders. Speech phonemes are alienated into consonants and vowels across languages. These phonemes are different in terms of production and perceptual mechanism. Persian has 6 vowels /i/, /e/, /a/, / acirc;/, /o/, and /u/. Vowels are the nucleus of the syllables and words, vowel errors can lead to disorders in speech perception process. Now the question arises as to whether the ability of vowel recognition in the presence of babble noise is influenced by age, signal to noise ratio, gender, and educational level? Also, if the above factors affect the recognition of the Persian vowel, which vowels are more vulnerable to these effects?Therefore, due to the absence of similar studies on the effect of the aforementioned factors on the recognition of Persian vowels, the present study examined the effect of age, signal to noise ratio, sex, and educational level on the recognition of Persian vowel in the fourth and fifth decades of life. This observational and cross sectional study was performed on 60 adults with normal hearing in the age range of 3049 years with mean and standard deviation (SD) of 38.88 ±6.23 years old (thirty people aged 30 to 39 years old with average age and standard deviation (SD) of 33.40 ±2.35 years and thirty aged 40 to 49 years with average age and standard deviation (SD) of 44.73 ±2.33 years) from available samples. After the auditory and speech evaluation, the recognition of Persian vowels were examined in consonantvowelconsonant syllable in the presence of babble noise in signaltonoise ratios of 0, 5 and 10, along with the randomized presentation of stimuli to the right ear. The purpose of the random presentation of syllables in the present study was to avoid memorizing words.Comparison the recognition score of six Persian vowels showed significant differences in three signaltonoise ratios (p = 0.001). Also, comparison the vowels recognition scores were significant in two age ranges of 3039 and 4049 years old in three signaltonoise ratios (p = 0.001). However, not found significant differences between the sexes (P= 0.991) and different educational levels (P= 0.282). Also, in three signal to noise ratios of 0, 5 and 10, the recognition scores of the front vowels were better than the back vowels. In signaltonoise ratios of 0 and 5, the highest mean of recognition score was associated with / a / vowel and in the signaltonoise ratio of 10 with / i / was present. Also, there was the lowest mean of recognition score in signaltonoise ratios 0, 5 and 10 with / u / vowel. The present study showed that the average recognition of Persian vowels is affected by age, signaltonoise ratio, and type of vowel. As the age increases and the signaltonoise ratio decreases, the average recognition score of the vowels decreases significantly in the presence of babble noise