Digital evaluation of the effect of noise on speech: signal/noise ratio

Author(s)

Vanessa Luisa Destro Fidêncio

• Document type: Master's Dissertation
• Press: Bauru.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Bauru (FOB/SDB)
• Defense date: 2013-08-23

Examining board members

Adriane Lima Mortari Moret; Joao Candido Fernandes; Ticiana Cristina de Freitas Zambonato

• Advisor: Adriane Lima Mortari Moret

Abstract

Noise is a factor that contributes negatively to the ability to understand speech, which can harm the development of children with hearing impairment. In classrooms, speech is rarely transmitted to children without interference from background noise. At the same time, the effective transmission of auditory information is essential for better academic performance. In most learning environments, which further interferes so there is a good speech perception is the signal/noise ratio (S/N). The Personal Frequency Modulation (FM) Systems serves as the most effective way to improve the uptake of speech signal and eliminate the effects of distance, noise and reverberation in the educational environment. Objective: To evaluate the S/N ratio that hearing impaired children are exposed in a school environment and compare with the speech reception threshold in noise. Methods: The study was conducted with children with hearing impaired and spoken language established, users of a hearing aids and/or cochlear implant (CI) coupled to FM system. The measurement of signal to noise ratio was achieved by the use of a portable digital recorder and an audio processing program for computer. To assess speech perception in noise was applied the Brazilian version of the Hearing in Noise Test (HINT), in two stages: first with the child using only their hearing aid\'s and/or CI and a second time with FM system coupled to individual device. Results: All children had better speech perception in noise using the FM system. Only in a one classroom the S/N ratio is adequate. It was observed that the position of the student in the classroom really affect the quality of the S/N ratio to which it is exposed. It was also proven that the higher the number of students, the lower the S/N ratio of the classroom. The S/N ratio of the classroom in a real school showed up with a value closer to the S/N ratio in which the patient can understand speech using the FM system, demonstrating that the use of this device is essential to better understand speech in these environments. (AU)

• FAPESP's process: 11/04821-3 - Digital evaluation of effect of noise on speech: the signal to noise ratio
• Grantee: Vanessa Luisa Destro Fidêncio
• Support Opportunities: Scholarships in Brazil - Master