Keywords

1 Introduction

In China, there are about 120 million people with hearing impairment at present, a considerable part of the causes of hearing impairment in young people are related to long-term use of earphones. Bad habits of using earphones and long-term wearing of uncomfortable earphones will cause ear injury [1]. So it is very important to minimize the physical damage of earphones and to improve the comfort of wearing earphones for a long time.

Studies have shown that 45% of headphone users consider the comfort of headphones as the primary consideration when purchasing headphones [2]. Unreasonable earphone shape is not only easy to fall off when wearing, but also easy to cause discomfort such as local pressure and swelling pain of the wearer. Recent research has found that extending the shape of earphone and earplug can make the wearer feel more comfortable, but also not easy to fall off [3].

The data of minors’ ears is the basis of the design of earphones, earmuffs and ear protection articles. The length, width and proportion of minors’ external ear contour should be fully considered in the design. At present, most of the researches on the characteristics of the ear are on adults, but few on minors. Qi Na [4] et al. studied the auricle morphological characteristics of 202 adult women and 202 adult men, and gave the representative average ear details according to the statistical results, but did not include the ear data of minors. Yin Xingzhong [5] and others measured the auricles of 120 young students aged 19-23. The measurement tool is Martin caliper, and the measurement items include 6 indexes of left and right auricles. Jiancai [6] et al. studied the auricle development of 110 children in Changsha area. The subjects were 2–12-year-old minors, mainly providing data reference for plastic surgeons to choose the time of ear reconstruction and the size of cartilage scaffold carving.

In this paper, 532 minors in northern China were studied in order to provide data support for the design of earphones, earmuffs and ear protectors.

2 Experiment Method

The measurement items include ear length and ear width. The definitions of these two measurement items come from GB/T 5703:2010 [7]. We have made a manual measurement with a Martin scale. Each measurement personnel have been trained in the early stage and have passed the measurement assessment. During the measurement, the subjects sat on the chair with their eyes flat in front of them and remained motionless. The tester held the Martin ruler on the right side of the subject and measured the length and width of the right ear.

3 Experimental Subject

The sample of this sampling is 532 minors aged 12–17 in northern China. The distribution of subjects is shown in Table 1.

Table 1. Information of subjects
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4 Data Analysis

4.1 Ear Data Differences Between Different Genders

The statistical values of ear length and width for boys and girls are shown in Table 2.

Table 2. The statistical values of ear length and width
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It can be seen from Table 2 that the average ear length of boys is 62.3 mm, and that of girls is 58.9 mm. The average ear length of boys is 3.4 mm larger than that of girls. The mean ear width of boys was 35.5 mm, that of girls was 33.5 mm, and that of boys was 2 mm larger than that of girls.

Independent sample test was conducted. It was found that there was a significant difference in the ear length between different genders (P < 0.05), and there was no significant difference in the ear width between different genders (P < 0.05).

4.2 Ear Data Differences of Different Age Groups

The data of ear length and ear width of different ages are shown in Fig. 1.

Fig. 1.
figure 1

Ear length of minors of different ages

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It can be seen from Fig. 1 and Fig. 2 that the ear length and ear width of boys increase with age. The length of ear increased from 61.1 mm in 12–13 years old to 63.4 mm in 16–17 years old, and the width of ear increased from 35.3 mm in 12–13 years old to 35.7 mm in 16–17 years old, However, there was no significant difference between the two groups (P < 0.05), the difference between the two groups was not significant (P < 0.05).

Fig. 2.
figure 2

Ear width of minors of different ages

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5 Conclusion

The data of minors’ ears is the basis for the design of earphones, earmuffs and ear protectors. The length, width and proportion of the external ear contour of minors should be fully considered in the design. In this study, we measured the facial ear length and facial ear width of 532 minors aged 12–17 in northern China, and grouped them according to age and gender, and analyzed them by statistical methods. The statistical results showed that there was significant difference in the length of facial ears between different genders (P < 0.05), and there was no significant difference in the width of facial ears between different genders (P < 0.05). The length and width of the ears increased with age, but there was no significant difference between the appearance ear length and the appearance ear width between the ages (P < 0.05). The research results can provide data support for the ergonomic design of earphones, earmuffs and other ear products.