Personal Listening Devices Users Research Articles

Smart Phones and Personal Listening Devices - Tinnitus & Hearing Impairment in Adolescent and Young Adult Earphone Users

OBJECTIVES To determine the frequency of tinnitus & hearing impairment in adolescent and young adult earphone users with smartphones and other personal listening devices.METHODOLOGY This prospective & descriptive study involving children with glue ears was conducted in the ENT Department of Medical Teaching Institute, Hayatabad Medical Complex, Peshawar, from Jan 1, 2022, to Sep 30, 2022. Personal listening device (PLD) users aged 12-25 years with complaints of tinnitus and hearing impairment were examined. Conductive hearing loss was excluded by audiological testing. The frequency of resultant hearing loss and tinnitus was calculated. The information obtained was analyzed using SPSS v 26.0 for windows. A Chi square test was performed to determine the significance of tinnitus & hearing impairment in earphones and other PLD users.RESULTS A total of 163 patients were included in the study. The patient’s age range was 12-25 years, with a mean age of 18.03 years and a standard deviation of ± 3.575. There were 117 males and 46 females. The male: female ratio was of 2.54:1.Tinnitus was present in 73% and Hearing impairment in 54.4% of the patients. The chi-square test and p-values determined showed that both tinnitus and hearing loss occurred in many patients using personal listening devices.CONCLUSION Tinnitus and hearing impairment occurs in a significant number of those who use personal listening devices. Their inappropriate use can lead to auditory system damage. It is recommended that PLD users undergo periodic audiological testing to detect early hearing loss and tinnitus to minimize damage to the ear.

Examining the Profile of Noise-Induced Cochlear Synaptopathy Using iPhone Health App Data and Cochlear and Brainstem Electrophysiological Responses to Fast Clicks Rates.

Little is known about objective classifying of noise exposure risk levels in personal listening device (PLD) users and electrophysiologic evidence of cochlear synaptopathy at very fast click rates. The aim of the study was to objectively classify noise exposure risk using iPhone Health app and identify signs of cochlear synaptopathy using behavioral and electrophysiologic measures. Thirty normal-hearing females (aged 18-26 years) were grouped based on their iPhone Health app's 6-month listening level and noise exposure data into low-risk and high-risk groups. They were assessed using a questionnaire, extended high-frequency (EHF) audiometry, QuickSIN test, distortion-product otoacoustic emission (DPOAE), and simultaneous recording of electrocochleography (ECochG) and auditory brainstem response (ABR) at three click rates (19.5/s, 97.7/s, 234.4/s). A series of ANOVAs and independent samples t -test were conducted for group comparison. Both groups had within-normal EHF hearing thresholds and DPOAEs. However, the high-risk participants were over twice as likely to suffer from tinnitus, had abnormally large summating potential to action potential amplitude and area ratios at fast rates, and had slightly smaller waves I and V amplitudes. The high-risk group demonstrated a profile of behavioral and objective signs of cochlear synaptopathy based on ECochG and ABR recordings at fast click rates. The findings in this study suggest that the iPhone Health app may be a useful tool for further investigation into cochlear synaptopathy in PLD users.

Use of Personal Listening Devices and Knowledge/Attitude for Greater Hearing Conservation in College Students: Data Analysis and Regression Model Based on 1009 Respondents.

Given the concern regarding increased hearing loss in young people who use personal listening devices (PLDs), the present study analyzes the experience of PLDs among college students to identify their knowledge of and attitude toward hearing conservation. It also explains their relationship between knowledge of hearing loss and attitude-related hearing conservation as a questionnaire response using a regression model. A total of 1009 Korean college students responded to an online questionnaire. As a survey tool, the Personal Listening Device and Hearing Questionnaire was adapted as a Korean version with 78 modified items under 9 categories. Using principal component analysis, specific factors were extracted, and their relationships and paths were confirmed using multiple regression analysis. The results of the knowledge category of the questionnaire indicate that most respondents knew how to maintain healthy hearing and understood the signs of hearing loss. Regardless, many college students habitually use PLDs at high levels in noisy environments; they do not recognize how to prevent hearing loss. Even though they continue their current use pattern for PLDs, they also had a positive attitude toward receiving more information about hearing conservation. According to the regression model, the students’ self-reported hearing deficits were due to the volume rather than the frequent use. Interestingly, knowledge about hearing loss may encourage students to develop a positive attitude toward reasonable restriction of PLD use. When PLD users have detailed knowledge about the hearing loss provided by professionals, we believe that most will avoid serious hearing problems and its risks and maintain a judicious attitude toward their own conservation.

The Effects of Short-Term and Long-term Hearing Changes on Music Exposure: A Systematic Review and Meta-Analysis.

The present study explores the scientific evidence on whether music exposure temporarily or permanently affects hearing sensitivity in young adults. Six electronic databases were searched using related keywords for the four categories of personal listening devices, listening habits, hearing outcomes, and age. The Hedges’ g and its 95% confidence intervals (CIs) were estimated. A Higgins I2 was also used to check for heterogeneity. To test for publication bias, funnel plots were drawn using Egger’s regression. Based on the inclusion criteria, 16 studies were divided into two groups to identify short-term hearing changes (n = 7) and long-term hearing changes (n = 9). In the short term, there was no significant immediate change in the thresholds or amplitudes after the music exposure, although pure-tone thresholds (PTAs) and distortion product otoacoustic emissions (DPOAEs) did show the highest effect size (−0.344, CI −0.727 to 0.038) and (0.124, CI −0.047 to 0.296) at 4 kHz. On the other hand, for long-term hearing changes, the PTA provided the highest effect size at 6 kHz (−0.525, CI −0.897 to −0.154) and 8 kHz (–0.486, CI −0.819 to −0.152), while also implying that habitual and repeated personal listening device (PLD) usage can act on some significant hearing changes in audiological tests. We conclude that the use of a PLD produces a few temporary hearing changes at 4 kHz after its use but that the changes are then reversed. However, it is important to note heavy PLD users’ experience regarding permanent changes in their hearing thresholds at high frequencies, and the public should be educated on this issue.

Prevalence of sensorineural hearing loss among medical students who are chronic mobile phone and earphone users in Trivandrum, South Kerala, India

Introduction: Hearing loss occurs as age increases, but these days seen affecting young adults as well. This could be due to the current increasing trend of chronic usage of personal listening devices (PLDs) such as mobile phones and earphones, which causes damage to the inner hair cells of the ear. Objectives: To study the prevalence of chronic PLD users among medical students and to assess the proportion of sensorineural hearing loss among them. To assess the perceived effects of listening to PLDs among chronic and non-chronic users of PLDs in medical students. Materials and Methods: A cross sectional study was done among 420 medical students of Dr. Somervell Memorial CSI Medical College in 2016. Basic information was collected from each student using a self administered predesigned and pretested questionnaire and chronic users were selected and subjected to pure tone audiometry and otoacoustic emissions (OAE). Results: Of the 420 students consented for the study, 44% were chronic users of PLDs. 120 students were subjected to audiometry and OAE. The total prevalence of sensorineural hearing loss was found to be 5% with high frequency hearing loss and 18.3% for low frequency hearing loss OAE results were normal in all individuals. The main associated complaints were poor academic performance, lack of sleep, limb pain and road side accidents. Conclusion: This study concluded only mild degree sensorineural hearing loss among chronic users of PLDs. However the associated complaints such as poor academic performance and roadside accidents were comparatively more in chronic users than non-chronic users. Keywords: India, Kerala, Medical students, Personal listening devices (PLDs), Sensorineural hearing loss.

A preliminary study on time-compressed speech recognition in noise among teenage students who use personal listening devices

Objective: To compare speech perception obtained with different time compression rates in teenagers that do or do not use personal listening devices (PLDs).Design: Teenagers in a high school were recruited to complete questionnaires reporting their recreational noise exposure using PLDs. The dose of individual recreational noise exposure was calculated. The individuals with the most and least doses of recreational noise were selected and grouped into PLD users and non-PLD users. Normal rate and time-compressed (60% and 70%) speech recognition in quiet and noisy conditions was measured.Study sample: PLD user and non-PLD user group each included 20 participants.Results: ANOVA analysis showed that the effect of group, background, compression rate, and interactions between any two factors are significant. Post hoc analysis showed that the speech recognition scores with normal rate in quiet and noise and those obtained from time-compressed speech in the quiet condition were not significantly different between PLD users and non-PLD users. However, differences in the time-compressed speech recognition scores (60% and 70%) in noisy conditions between the two groups were statistically significant.Conclusions: The fast-speed speech recognition in noise decreased significantly in PLD users compared with that in non-PLD users selected by extreme entertainment exposure.

Early Indication of Noise-Induced Hearing Loss in Young Adult Users of Personal Listening Devices.

The recent integration of portable music players into cell phones has further increased the use of personal listening devices (PLD) among young adults, raising concerns about potentially hazardous effects on hearing. Assessment of young adults' hearing ability and listening preferences by subjective and objective measurement. Young adult users of PLDs (n = 50; 30 females, 20 males; mean age = 24.1 ± 4.2 years; average PLD use = 6.1 ± 2.1 years) were included. Subjective assessment of listening preferences was performed via a questionnaire as well as objective assessment of preferred volume levels in different background noise environments and hearing tests. Preferred volume levels were significantly correlated with hearing thresholds. Most participants exhibited safe listening behavior according to National Institute for Occupational Safety and Health criteria. We identified a substantial high-risk subgroup of PLD users (22% of participants, daily use ⩾2 h at ⩾91 dB) in which pure tone audiometry showed increased hearing thresholds at 4000 and 6000 Hz, potentially indicating an early manifestation of noise-induced hearing loss (NIHL). These findings suggest that preventive measures may be warranted to prevent a future increase of clinically relevant NIHL among heavy users of PLDs.

Personal Listening Devices in Australia: Patterns of Use and Levels of Risk.

Personal listening devices (PLDs) have the potential to increase the risk of noise-induced hearing loss (NIHL) for users. The present study aimed to investigate the nature and extent of the risk posed, by describing the user profile of a PLD population, identifying listening habits of that population, and examining whether PLD risk status is associated with hearing damage. A sample of 4,185 Australian PLD users completed an online survey about listening behaviors and hearing health. Listeners were characterized as low, high, or very high-risk based on daily noise dose estimates calculated from self-reported listening volume and durations. Listening patterns and hearing difficulties were examined in relation to risk status. Results indicated differences in listening volumes and durations with respect to age, with higher listening volumes reported for environments with greater background noise. Fifteen percent of participants' usage was classified as posing a potential risk to hearing, with a significantly greater proportion of younger people in higher-risk categories. Forty-one percent of participants reported feeling they have a hearing loss, with ∼20% reporting difficulties with speech in noise. For 18- to 35-year-olds, higher-risk status was associated with a greater proportion of self-reported hearing difficulties, including perceived poorer speech perception. These results have implications for hearing health promotion activities and suggest that messages should focus on either volume levels or durations depending on the particular activity in which the PLD is used. In addition, the results underline the importance of placing PLD exposure in the context of individuals' wider noise exposure. Although PLD use alone is not placing the majority of users at risk, it may be increasing the likelihood that individuals' cumulative noise exposure will exceed safe levels.

WHO Environmental Noise Guidelines for the European Region: A Systematic Review on Environmental Noise and Permanent Hearing Loss and Tinnitus.

Background: Hearing loss is defined as worsening of hearing acuity and is usually expressed as an increase in the hearing threshold. Tinnitus, defined as “ringing in the ear”, is a common and often disturbing accompaniment of hearing loss. Hearing loss and environmental exposures to noise are increasingly recognized health problems. Objectives: The objective was to assess whether the exposure-response relationship can be established between exposures to non-occupational noise and permanent hearing outcomes such as permanent hearing loss and tinnitus. Methods: Information sources: Computer searches of all accessible medical and other databases (PubMed, Web of Science, Scopus) were performed and complemented with manual searches. The search was not limited to a particular time span, except for the effects of personal listening devices (PLDs). The latter was limited to the years 2008–June 2015, since previous knowledge was summarized by SCENIHR descriptive systematic review published in 2008. Study eligibility criteria: The inclusion criteria were as follows: the exposure to noise was measured in sound pressure levels (SPLs) and expressed in individual equivalent decibel values (LEX,8h), the studies included both exposed and reference groups, the outcome was a permanent health effect, i.e., permanent hearing loss assessed with pure-tone audiometry and/or permanent tinnitus assessed with a questionnaire. The eligibility criteria were evaluated by two independent reviewers. Study appraisal and synthesis methods: The risk of bias was assessed for all of the papers using a template for assessment of quality and the risk of bias. The GRADE (grading of recommendations assessment, development, and evaluation) approach was used to assess the overall quality of evidence. Meta-analysis was not possible due to methodological heterogeneity of included studies and the inadequacy of data. Results: Out of 220 references identified, five studies fulfilled the inclusion criteria. All of them were related to the use of PLDs and comprised in total of 1551 teenagers and young adults. Three studies used hearing loss as the outcome and three tinnitus. There was a positive correlation between noise level and hearing loss either at standard or extended high frequencies in all three of the studies on hearing loss. In one study, there was also a positive correlation between the duration of PLD use and hearing loss. There was no association between prolonged listening to loud music through PLDs and tinnitus or the results were contradictory. All of the evidence was of low quality. Limitations: The studies are cross-sectional. No study provides odds ratios of hearing loss by the level of exposure to noise. Conclusions: While using very strict inclusion criteria, there is low quality GRADE evidence that prolonged listening to loud music through PLDs increases the risk of hearing loss and results in worsening standard frequency audiometric thresholds. However, specific threshold analyses focused on stratifying risk according to clearly defined levels of exposure are missing. Future studies are needed to provide actionable guidance for PLDs users. No studies fulfilling the inclusion criteria related to other isolated or combined exposures to environmental noise were identified.

Extended high frequency audiometry in users of personal listening devices

PurposeNoise exposure leads to high frequency hearing loss. Use of Personal Listening Devices may lead to decline in high frequency hearing sensitivity because of prolonged exposure to these devices at high volume. This study explores the changes in hearing thresholds by Extended High Frequency audiometry in users of personal listening devices. Material and methodA descriptive, hospital based observational study was performed with total 100 subjects in age group of 15–30years. Subjects were divided in two groups consisting of 30 subjects (Group A) with no history of Personal Listening Devices use and (Group B) having 70 subjects with history of use of Personal Listening Devices. Conventional pure tone audiometry with extended high frequency audiometry was performed in all the subjects. ResultSignificant differences in hearing thresholds of Personal Listening Device users were seen at high frequencies (3kHz, 4kHz and 6kHz) and extended high frequencies (9kHz, 10kHz, 11kHz, 13kHz, 14kHz, 15kHz and 16kHz) with p value <0.05. Elevated hearing thresholds were observed in personal listening devices users which were directly proportional to volume and duration of usage. ConclusionIn present study no significant changes were noted in hearing thresholds in PLD users before 5years of PLD use. However, hearing thresholds were significantly increased at 3kHz, 10kHz, 13kHz in PLD users having >5years usage at high volume. Thus, it can be reasonably concluded that extended high frequencies can be used for early detection of NIHL in PLD users.

Hearing Risk among Young Personal Listening Device Users: Effects at High-Frequency and Extended High-Frequency Audiogram Thresholds.

The usage of personal listening devices (PLDs) is associated with risks of hearing loss. The aim of this study is to evaluate the effects of music exposure from these devices on high-frequency hearing thresholds of PLD users. A total of 282 young adults were questioned regarding their listening habits and symptoms associated with PLD listening. Their audiogram thresholds were determined at high (3-8 kHz) frequencies and extended high frequencies (EHFs, 9-16 kHz). The preferred listening volumes of PLD users were used to compute their overall 8-h equivalent music exposure levels (LAeq8h). Approximately 80% of the subjects were regular PLD users. Of these, 20.1% had LAeq8h of ≥75 dBA, while 4.4% of them had LAeq8h of ≥85 dBA, which carries a high risk of hearing damage. Compared with those exposed to LAeq8h of <75 dBA, subjects who had LAeq8h of ≥75 dBA reported a significantly higher incidence of tinnitus and difficulty in hearing others immediately after using PLDs. PLD users who were exposed to LAeq8h of ≥75 dBA and had been using their devices for ≥4 years also showed significantly higher mean audiogram thresholds compared with non-users at most EHFs tested. In addition, the thresholds of PLD users at EHFs showed a weak but significant positive correlation with their LAeq8h. The present findings suggest that excessive exposure to music among PLD users may lead to initial effects on their hearing at very high frequencies.

Gender Factors that Affect Health and Hearing Acuity in Personal Listening Device Users and Non-Users

Gender Factors that Affect Health and Hearing Acuity in Personal Listening Device Users and Non-Users Background: Research has revealed that differences in hearing levels exist among males and females due to physiological differences between genders. However, few studies have explored gender differences involving the link between hearing levels and frequency of exposure to noise, hearing protection, duration and intensity level of personal listening device (PLD) use, and fitness factors across the lifespan. Methods: Data were analyzed from 115 males and females (ages 18 to 84) recruited from Oxford, Ohio. Participants were separated into two groups: PLD-users and PLD non-users, depending on their usage. Both groups completed audiometric and health-related fitness testing. Results: Males were more likely to listen to music at potentially harmful levels (85 dBA) in silence (p= 0.002). Although the majority of participants listened at “safe” levels, males were more likely to listen at louder and potentially dangerous levels in silence than females. Waist-to-hip ratio was positively correlated with hearing levels in both genders. Only 23% of participants reported using hearing protection: half female, half male. Participants who used PLDs for a greater number of years had better traditional frequency hearing thresholds than non-PLD users. Conclusion: A majority of those who have been using PLDs for a greater number of years are younger adults whose hearing acuity has not yet been greatly affected by degenerative effects of aging. Medical advancements and improved fitness levels may protect the younger generations’ hearing acuity as they age. Gender differences related to hearing loss can provide valuable information about risk factors for developing hearing loss throughout aging.

Music listening behavior, health, hearing and otoacoustic emission levels.

This study examined the relationship between hearing levels, otoacoustic emission levels and listening habits related to the use of personal listening devices (PLDs) in adults with varying health-related fitness. Duration of PLD use was estimated and volume level was directly measured. Biomarkers of health-related fitness were co-factored into the analyses. 115 subjects ages 18–84 participated in this study. Subjects were divided into two sub-groups; PLD users and non-PLD users. Both groups completed audiological and health-related fitness tests. Due to the mismatch in the mean age of the PLD user versus the non-PLD user groups, age-adjusted statistics were performed to determine factors that contributed to hearing levels. Age was the most significant predictor of hearing levels across listening and health-related fitness variables. PLD user status did not impact hearing measures, yet PLD users who listened less than 8 hours per week with intensities of less than 80 dBA were found to have better hearing. Other variables found to be associated with hearing levels included: years listening to PLD, number of noise environments and use of ear protection. Finally, a healthy waist-to-hip ratio was a significant predictor of better hearing, while body mass index approached, but did not reach statistical significance.

Evaluation of early hearing damage in personal listening device users using extended high-frequency audiometry and otoacoustic emissions

Although sound exposure from personal listening devices (PLDs) could potentially lead to noise-induced hearing loss (NIHL), the actual hearing risk associated with the use of these devices is still unclear. In this study, early hearing effects related to PLD usage were evaluated in 35 young adult PLD users (listening for >1 h/day, at >50% of the maximum volume setting of their devices) and their age- and sex-matched controls using a combination of conventional and extended high-frequency audiometry as well as transient-evoked otoacoustic emission (TEOAE) and distortion product of otoacoustic emission (DPOAE) measurements. The mean listening duration of the PLD users was 2.7 ± 1.0 h/day while their estimated average listening volume was 81.3 ± 9.0 dBA (free-field corrected). Typical signs of NIHL were not detected in the audiogram of PLD users and their audiometric thresholds at most of the conventional test frequencies (0.25-8 kHz) were comparable with those obtained from controls. However, compared with the controls, mean hearing thresholds of PLD users at many of the extended high-frequencies (9-16 kHz) were significantly higher. In addition, TEOAE and DPOAE amplitudes in users were reduced compared with controls. The deterioration of extended high-frequency thresholds and the decrease in DPOAE amplitudes were more evident in the users' right ears. These results indicate the presence of an early stage of hearing damage in the PLD user group. Preventive steps should be taken as the initial hearing damage in these users could eventually progress into permanent NIHL after many years of PLD use.

Low body mass index and jaw movement are protective of hearing in users of personal listening devices

Sound pressure level delivered through personal listening devices (PLDs) and reaching the ear drum might be affected by body size and jaw movements. This study aimed to investigate whether jaw movement and/or smaller body mass index (BMI) resulted in decrease of sound pressure level within the ear canals of PLD users via an earbud earphone. Case series. Forty-five normal-hearing subjects (16 males; mean age, 23.3 years) participated in this study. A probe-microphone system was used to measure sound pressure level in the external ear canal with music delivered from a media player via an earbud earphone. Test materials consisted of two 20-second excerpts from a heavy metal music piece. Subjects were instructed to adjust the volume of the media player to conform to three conditions for sound pressure measurement: comfortable, loud, and maximum. Measurements were then repeated while subjects mimicked chewing action under the same listening conditions. Sound pressure levels were significantly lower when measured with jaw movement than without jaw movement (P < .05). Sound pressure levels monitored with/without jaw movement were generally lower in subjects with a BMI<23 than those with a BMI ≥ 23 (P < .05). Jaw movement and low BMI (<23) reduced the overall sound level of PLDs at the ear canal. Sound pressure levels detected in the external ear canal of our subjects using earbud earphones were significantly lower under conditions of jaw movement/BMI <23. Our research invites further studies on a larger group of PLD users to correlate these variables with hearing threshold shifts over time.

Hearing risk associated with the usage of personal listening devices among urban high school students in Malaysia

ObjectivesTo investigate listening habits and hearing risks associated with the use of personal listening devices among urban high school students in Malaysia. Study designCross-sectional, descriptive study. MethodsIn total, 177 personal listening device users (13–16 years old) were interviewed to elicit their listening habits (e.g. listening duration, volume setting) and symptoms of hearing loss. Their listening levels were also determined by asking them to set their usual listening volume on an Apple iPod TM playing a pre-selected song. The iPod's sound output was measured with an artificial ear connected to a sound level meter. Subjects also underwent pure tone audiometry to ascertain their hearing thresholds at standard frequencies (0.5–8 kHz) and extended high frequencies (9–16 kHz). ResultsThe mean measured listening level and listening duration for all subjects were 72.2 dBA and 1.2 h/day, respectively. Their self-reported listening levels were highly correlated with the measured levels (P < 0.001). Subjects who listened at higher volumes also tend to listen for longer durations (P = 0.012). Male subjects listened at a significantly higher volume than female subjects (P = 0.008). When sound exposure levels were compared with the recommended occupational noise exposure limit, 4.5% of subjects were found to be listening at levels which require mandatory hearing protection in the occupational setting. Hearing loss (≥25 dB hearing level at one or more standard test frequencies) was detected in 7.3% of subjects. Subjects' sound exposure levels from the devices were positively correlated with their hearing thresholds at two of the extended high frequencies (11.2 and 14 kHz), which could indicate an early stage of noise-induced hearing loss. ConclusionsAlthough the average high school student listened at safe levels, a small percentage of listeners were exposed to harmful sound levels. Preventive measures are needed to avoid permanent hearing damage in high-risk listeners.

Preferred listening levels of personal listening devices in young teenagers: Self reports and physical measurements

Objective: To assess the potential risk of hearing loss to young listeners, due to the use of personal listening devices (PLDs). Design: The study included two parts: (1) A self-report questionnaire on music listening habits, and (2) Physical measurements of preferred listening levels, in quiet and in everyday background noise. Study sample: Young teenagers aged 13 to 17 years. Part 1 included 289 participants with mean age of 14 years. Part 2 included 11 and 74 participants (2A and 2B) with a mean age of 15 years. Eleven listened to PLDs in quiet conditions (2A) and 74 in everyday background noise (2B). Results: Questionnaire main findings indicated that most of the participants reported high or very high volume settings and demonstrated low awareness towards loud music listening consequences. Physical measurements corrected for diffuse field indicated mean preferred listening levels of: 82 (SD = 9) dBA in quiet, and 89 (SD = 9) dBA in the presence of background noise. The potential risk to hearing of PLDs users was calculated using the 8 hour equivalent level. Conclusion: More than 25% of the participants in the noisy condition were found to be at risk according to occupational damage risk criteria NIOSH, 1998.

Targeting Hearing Health Messages for Users of Personal Listening Devices

To summarize the literature on patterns and risks of personal listening device (PLD) use, which is ubiquitous among teenagers and young adults. The review emphasizes risk awareness, health concerns of PLD users, inclination to take actions to prevent hearing loss from exposure to loud music, and specific instructional messages that are likely to motivate such preventive actions. We conducted a systematic, critical review of the English-language scholarly literature on the topic of PLDs and their potential effects on human hearing. We used popular database search engines to locate relevant professional journals, books, recent conference papers, and other reference sources. Adolescents and young adults appear to have somewhat different perspectives on risks to hearing posed by PLD use. Messages designed to suggest actions they might take in avoiding or reducing these risks, therefore, need to be targeted to achieve optimal outcomes. We offer specific recommendations regarding the framing and content of educational messages that are most likely to be effective in reducing the potentially harmful effects of loud music on hearing in these populations, and we note future research needs.

Noise Exposure Estimates of Urban MP3 Player Users

To examine the sound level and duration of use of personal listening devices (PLDs) by 189 college students, ages 18-53 years, as they entered a New York City college campus, to determine whether noise exposure from PLDs was in excess of recommended exposure limits and what factors might influence exposure. Free-field equivalent sound levels from PLD headphones were measured on a mannequin with a calibrated sound level meter. Participants reported demographic information, whether they had just come off the subway, the type of PLD and earphones used, and duration per day and days per week they used their PLDs. Based on measured free-field equivalent sound levels from PLD headphones and the reported PLD use, per day 58.2% of participants exceeded 85 dB A-weighted 8-hr equivalent sound levels (L(Aeq)), and per week 51.9% exceeded 85 dB A-weighted 40-hr equivalent continuous sound levels (L(Awkn)). The majority of PLD users exceeded recommended sound exposure limits, suggesting that they were at increased risk for noise-induced hearing loss. Analyses of the demographics of these participants and mode of transportation to campus failed to indicate any particular gender differences in PLD use or in mode of transportation influencing sound exposure.

Comparing two methods to measure preferred listening levels of personal listening devices

The potential risk to hearing that mass-storage personal listening devices (PLDs) pose remains unclear. Previous research in this area has either focused on maximum outputs of these devices or on ear-canal measurements of listening levels that could not be compared to standards of occupational noise exposure. The purpose of this study was to compare two standard measurement protocols [ISO 11904-1 (2002), Switzerland; ISO 11904-2 (2004), Switzerland] for the measurement of preferred listening levels of PLD. Noise measurements, behavioral thresholds, and oral interviews were obtained from 30 (18-30 years) PLD users. Preferred listening levels for self-selected music were determined in quiet and background noise using a probe microphone, as well as in the DB-100 ear simulator mounted in KEMAR. The ear-canal measurements were compensated for diffuse-field. Only one of the subjects was found to be listening at hazardous levels once their reported daily usage was accounted for using industrial workplace standards. The variance across subjects was the smallest in the ear-canal measurements that were compensated for diffuse-field equivalence [ISO 11904-1 (2002), Switzerland]. Seven subjects were found to be listening at levels above 85 dBA based on measurements obtained in the KEMAR and then compensated for diffuse-field equivalence.