Original Article Analysis of sound pressure levels emitted by children’s toys Análise dos níveis de pressão sonora emitidos por brinquedos infantis Análisis de los niveles de presión sonora emitidos por juguetes infantiles Pricila Sleifer1, Maiara Santos Gonçalves2, Marinês Tomasi3, Erissandra Gomes4 ABSTRACT Métodos: Estudo transversal com brinquedos sonoros ofertados em lojas de comércio popular, chamado de setor Objective: To verify the levels of sound pressure emitted informal. Foram considerados brinquedos eletrônicos, mecâ- by non-certified children’s toys. nicos e musicais. A mensuração de cada produto foi realizada Methods: Cross-sectional study of sound toys available por um engenheiro acústico, em cabine isolada acusticamente, at popular retail stores of the so-called informal sector. por meio de um decibelímetro. Para obter os parâmetros Electronic, mechanical, and musical toys were analyzed. The sonoros de intensidade e frequência, os brinquedos foram measurement of each product was carried out by an acoustic acionados a uma distância de 10 e 50cm da orelha do pes- engineer in an acoustically isolated booth, by a decibel quisador. A intensidade foi verificada em nível de pressão meter. To obtain the sound parameters of intensity and sonora em decibéis dB(A) e a frequência, em hertz (Hz). frequency, the toys were set to produce sounds at a distance Resultados: Foram avaliados 48 brinquedos. Nas medidas of 10 and 50cm from the researcher’s ear. The intensity of a 10cm da orelha, foi registrada uma faixa de pressão sonora sound pressure [dB(A)] and the frequency in hertz (Hz) de 102±10 dB(A) e, a 50cm, a média foi de 94±8 dB(A), were measured. com p<0,05. A maioria dos brinquedos apresentou nível de Results: 48 toys were evaluated. The mean sound pressure pressão sonora acima de 85dB(A). A frequência variou de 10cm from the ear was 102±10 dB(A), and at 50cm, 94±8 413 a 6.635Hz, sendo que 56,3% dos brinquedos emitiram dB(A), with p<0.05. The level of sound pressure emitted som com frequência superior a 2.000Hz. by the majority of toys was above 85dB(A). The frequency Conclusões: Constatou-se que a maioria dos brinquedos ranged from 413 to 6,635Hz, with 56.3% of toys emitting emitiu sons com elevado nível de pressão. frequency higher than 2,000Hz. Conclusions: The majority of toys assessed in this Palavras-chave: jogos e brinquedos; medição de ruído; research emitted a high level of sound pressure. criança. Key-words: play and playthings; noise measurement; RESUMEN child. Objetivo: Verificar los niveles de presión sonora emitidos RESUMO por juguetes infantiles sin acreditación. Métodos: Estudio transversal con juguetes sonoros Objetivo: Verificar os níveis de pressão sonora emitidos ofrecidos en tiendas de comercio popular, del dicho sector por brinquedos infantis sem certificação. informal. Se consideraron juguetes electrónicos, mecánicos y Instituição: Universidade Federal do Rio Grande do Sul (UFRGS), Porto Endereço para correspondência: Alegre, RS, Brasil Pricila Sleifer 1Doutora em Ciências Médicas pela UFRGS; Professora Adjunta do Curso Avenida Lavras, 584, apto. 302 – Petrópolis de Fonoaudiologia da UFRGS, Porto Alegre, RS, Brasil CEP 90420-040 – Porto Alegre/RS 2Mestre em Distúrbios da Comunicação Humana pela Universidade Federal E-mail: [email protected] de Santa Maria (UFSM), Santa Maria, RS, Brasil 3Fonoaudióloga do Centro Universitário Metodista da Faculdade Metodista Conflito de interesse: nada a declarar do Sul, Porto Alegre, RS, Brasil 4Doutor em Ciências Médicas pela UFRGS; Professor Adjunto do Curso de Recebido em: 20/9/2012 Fonoaudiologia da UFRGS, Porto Alegre, RS, Brasil Aprovado em: 31/1/2013 Rev Paul Pediatr 2013;31(2):218-22. Pricila Sleifer et al musicales. La medición de cada producto la realizó un inge- In Brazil, the tolerance limits for continuous or intermit- niero acústico en una cabina aislada acústicamente mediante tent noise postulated by the Regulatory Standard n. 15, by un decibelímetro. Para obtener los parámetros de intensidad the Ministry of Labor(7) are recommendations for adult oc- y frecuencia, los juguetes fueron accionados a una distancia cupational exposure to noise and cannot be extended to the de 10 y 50cm de la oreja del investigador. La intensidad fue pediatric population. Thus, there are currently no standards verificada en nivel de presión sonora en decibelios dB(A), y of noise exposure time for children, and the incidence of la frecuencia en hertz (Hz). temporary alteration of the hearing threshold or of NIHL Resultados: Se evaluaron 48 juguetes. En las medidas a is unknown in this population. In relation to toys, to be 10 cm de la oreja, se registró una franja de presión sonora released for sale, they should be according to the Brazilian de 102±10 db(A), y a 50cm de la oreja, el promedio fue de Standard (Norma Brasileira - NBR) 11786/92 – Toy Safety. 94±8 dB(A) (p<0,05). La mayoría de los juguetes presentó This norm requires that the noise generated by toys, regard- nivel de presión sonora superior a 85 dB(A). La frecuencia less of the age of the child, should not be greater than 85dB varió de 413 a 6635Hz, siendo que el 56,3% de los juguetes for continuous noise and 100dB for instant noise(13). The emitieron sonido con frecuencia superior a 2000Hz. toys nationally marketed should be certified by the National Conclusión: Se constató que la mayoría de los juguetes Institute of Metrology, Standardization, and Industrial emitió sonidos de elevado nivel de presión. Quality (Instituto Nacional de Metrologia, Normalização e Qualidade Industrial - Inmetro) complying with this rule. Palabras clave: juegos y juguetes; medición de ruido; The literature search conducted for this study showed that niño. the most common studies are those related to noise exposure in intensive care units in hospitals, fireworks, music-related Introduction activities, as well as the school environment. However, some studies are now focusing on the effects of noise produced by Games are allies of child development, guiding learn- toys in children(3-6,14-16). In Brazil, investigations(17-19) have ing through play and awakening the child’s interest in the shown that toys have sound levels that could damage chil- world(1-3). Therefore, playing is essential for the social, emo- dren’s hearing, calling attention to the need for a preventive tional, physical, and cognitive development of children(2). approach. Sound toys are part of this playing universe and, besides en- This study is justified by the fact that there is a large tertaining and assisting children in aspects of development, number of toys, with low cost, sold in the informal sector. It they stimulate the sensory pathways of hearing(3). However, is known that, in these cases, most toys do not have control caution is needed when providing sound-emitting toys to over sound levels. Thus, this study aimed to verify the sound children, once they can produce excessively intense noise, pressure level produced by children’s toys available in the causing risks to hearing health(3-6). informal sector retail trade. The human ear has a sound tolerance depending on the intensity and duration of exposure(7), a limit that must be Method respected especially for children undergoing oral language acquisition(8), since hearing is the primary sense that pro- A cross-sectional observational research design was em- vides the development of this ability(9). For the auditory ployed. The study selected toys offered at popular retail stores system under development, sensitivity to loud sounds may in the municipality of Porto Alegre, state of Rio Grande do be greater, as well as the level of damage(10). Sul, Brazil, from the so-called informal sector. The inclu- The systematic and prolonged exposure to sounds with sion criteria were having sound stimulus and not bearing a high sound pressure levels can a result in temporary or per- certification seal by Inmetro. All toys that met the criteria manent change in hearing thresholds(11), the latter known as were included in the research until the estimated number Noise Induced Hearing Loss (NIHL). This type of perma- was reached. nent damage may be the explanation for the high degrees of The sample size calculation was performed considering hearing impairment observed in children and adolescents, the values found in other studies(3-6,17,18), power of 90% and a since the intensity of the ambient noises often approaches level of significance of 5%. It was estimated the need for 40 damaging levels(4,12). toys to analyze the differences between the sound pressure 219 Rev Paul Pediatr 2013;31(2):218-22. Analysis of sound pressure levels emitted by children’s toys levels at different distances. We chose to increase the sample 108.6dB(A); 95%CI 91.8–96.3dB(A)), and 43 (89.6%) in 20%, in case there was need for exclusions. toys delivered sounds above 85dB(A). There were significant Thus, 48 toys were evaluated, among electronic, mechanic differences in loudness according to the distance (10 versus and musical toys, including those that imitate real musical 50cm) in which the toy stood (p<0.001). instruments and those who play recorded songs when some The resulting frequency spectra obtained in each toy was button is pressed. The toys were categorized by the presen- between 413 and 6635Hz. Among the 48 toys, 27 (56.3%) tation of the sound stimulus, followed by the classification issued a frequency between 2030 and 6635Hz. It can be of another similar study(18), in: emitting airflow (including observed that the higher the frequency, the higher the sound wind), percussion, and electronics. pressure level and the higher the likelihood of presenting The measurement of each product was performed by the sound pressure levels above 85dB(A).