Analysis of Output Levels of an MP3 Player: Effects of Earphone Type, Music Genre, and Listening Duration

BACKGROUND AND OBJECTIVES: To prevent noise induced hearing losses caused by listening to music with personal listening devices for young adults, this study was aimed to measure output levels of an MP3 and to identify preferred listening levels (PLLs) depending on earphone types, music genres, and listening durations. SUBJECTS AND METHODS: Twenty-two normal hearing young adults (mean=18.82, standard deviation=0.57) participated. Each participant was asked to select his or her most PLLs when listened to Korean ballade or dance music with an earbud or an over-the-ear earphone for 30 or 60 minutes. One side of earphone was connected to the participant’s better ear and the other side was connected to a sound level meter via a 2 or 6 cc-couplers. Depending on earphone types, music genres, and listening durations, loudness A-weighted equivalent (LAeq) and loudness maximum time-weighted with A-frequency sound levels in dBA were measured. RESULTS: Neither main nor interaction effects of the PLLs among the three factors were significant. Overall output levels of earbuds were about 10-12 dBA greater than those of over-the-ear earphones. The PLLs were 1.73 dBA greater for earbuds than over-the-ear earphones. The average PLL for ballad was higher than for dance music. The PLLs at LAeq for both music genres were the greatest at 0.5 kHz followed by 1, 0.25, 2, 4, 0.125, 8 kHz in the order. CONCLUSIONS: The PLLs were not different significantly when listening to Korean ballad or dance music as functions of earphone types, music genres, and listening durations. However, over-the-ear earphones seemed to be more suitable to prevent noise induce hearing loss when listening to music, showing lower PLLs, possibly due to isolation from the background noise by covering ears.

The Use of Acceptable Noise Level on Monaural and Binaural Amplification in Hearing Aids Fitting / 听力学及言语疾病杂志

Objective To compare the relationship of acceptable noise level (ANL) between monaural and binaural hearing aid in patients with bilateral moderate-to-severe hearing loss, and to investigate the clinical significance of the ANL in binaural hearing aid fitting and the predictive role in the hearing aid effect assessment.Methods A total of 15 patients with bilateral moderate-to-severe hearing loss were selected, and the most comfortable levels (MCL), background noise level (BNL) and calculate ANL were tested, respectively, in 4 conditions: without hearing aids, fitted only left ears, fitted only right ears and binaural fitting.Results The ANL in 15 subjects measured at 4 conditions were 18.87±5.26, 12.60±2.47, 12.00±2.90, and 5.13±1.25 dB S/N, respectively.The MCLs were 80.40±9.28, 63.73±5.15, 62.27±5.36, and 61.80±6.05 dB HL, respectively.The BNLs were 61.67±6.14, 51.13±3.94, 50.27±4.50, and 56.67±5.16 dB HL.The ANL difference between the only left and right fitting groups was not statistically significant(P>0.05).The ANL difference between the monaural or the binaural hearing aid group and without hearing aids group were statistically significant (P<0.05), respectively.Compared with the monaural hearing aid group, the binaural hearing aid group had significantly lower ANL(P<0.05).Conclusion For people with bilateral hearing loss, hearing aids can improve their ability to manage the background noise, and binaural hearing aid fitting is better than monaural.

Effects of relaxation training on sudden deafness patients with mild-to-moderate / 中国实用护理杂志

Objective To evaluate the effect of relaxation training on sudden deafness patients with mild or moderate grade.Methods 78 patients were divided into the observation group (38 cases) and the control group (40 cases).Besides usual care and nursing,the observation group was treated with relaxation training daily in the morning and evening.The pure tone audiometry scores before and after nursing intervention and treatment was compared between two groups.Results There was significant difference in threshold level between two groups.Conclusions Relaxation training was an effective nursing intervention for sudden deafness patients with mild-to-moderate grade.

Effect of Active Noise Cancelling Earphones on Preferred Listening Level When Listening to Portable Music Players in Noisy Environments / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Active noise cancelling (ANC) is a technology that can reduce external noise by producing a signal that is similar to noise but different in that it has an opposite phase to noise. Nowadays ANC has become an important technology in the field of hearing aids, but many studies have not focused on the effect of ANC of earphones when listening to portable music players. In this study, we aimed to evaluate whether ANC earphones can effectively reduce external noise and lower the preferred listening level. SUBJECTS AND METHOD: Three different earphones (Ear-canal, On-the-ear, Covering-the-ear) were tested in three different noise environments. Nine participants were tested in 10 experiments. First, through the real ear measurement (REM) system, we evaluated the differences in sound pressure level when the ANC was either turned on or off. Second, we evaluated the effects of ANC on Preferred Listening Level (PLL) for participants listening to the same song with different earphones. Through the REM system, we evaluate the level of sound pressure level when participants controlled the volume and felt most comfortable with the volume level. RESULTS: All three types of earphones showed statistically significant effects on noise reduction when ANC was turned on. The noise reduction effect was most prominent with the Ear-canal earphone. All three types of earphones also showed statistically significant effect on PLL reduction. CONCLUSION: ANC earphones may be helpful in noise reduction and preventing noise induced hearing loss when listening to music in noisy environments. Among the three types of earphones, Ear-canal earphone seems to be the most effective in noise reduction.