Volume Control Setting Research Articles

Listening Habits to Music during COVID-19 Pandemic: Is There a Risk to Hearing?

Abstract Background The coronavirus disease 2019 (COVID-19) pandemic introduced a unique situation by consigning people to their homes, with free time for music listening, joined with increased anxiety and stress levels. The question arises whether listening habits to music have changed during the pandemic. Such a change in listening habits might pose a greater potential risk to hearing than in routine days. Purpose To evaluate listening habits to music using earphones during the COVID-19 pandemic and assess if any change occurred in these habits compared with routine days before the pandemic. Research Design Self-reported listening habits were collected using a purpose-built questionnaire submitted online. Study Sample In total, the questionnaire was distributed among 242 young adults aged 18 to 30 years (mean: 24.3 ± 2.8). A total of 192 participants, regular listeners to music using earphones, provided information concerning their listening habits. Data Collection and Analysis Collected listening habits included: listening levels, duration, and frequency of listening during the pandemic compared with routine days. Symptoms and circumstances that occurred following music listening were reported as well. We compared statistically listening habits of participants that stayed home during the pandemic versus those that kept their office routine. In addition, we performed statistical analysis on hearing symptoms following unsafe versus safe music listeners. Results Most reported listening durations were 2 to 4 days (28.5%) and 7 days a week (29.7%), for at least 30 minutes, at high to very high listening levels, and volume control settings at 75 to 100%. Almost 50% of the participants reported a change in their listening habits during the pandemic, mainly a more frequent and longer listening duration. Overall, 29.1% of the participants were at potential risk of hearing loss due to unsafe listening habits. Conclusion The change in listening habits during the COVID-19 pandemic underscores the need to monitor listening habits and raise awareness of the one cause for hearing loss that can be prevented.

WPŁYW OSOBISTYCH SYSTEMÓW MUZYCZNYCH NA SŁUCH U MŁODYCH DOROSŁYCH: BADANIE KWESTIONARIUSZOWE

BackgroundNoise exposure damages cochlear hair cells resulting in sensorineural hearing loss along with other symptoms like tinnitus and vertigo. One source of loud sound exposure in young adults is personal music systems (PMS). The present study investigated the auditory- related symptoms in regular PMS users by administering a questionnaire on PMS usage and associated symptoms in individuals who were regular users of PMS and compared results with non-regular PMS users.Material and methodsThere were 260 young adults who participated in the study. Individuals who used PMS for ≥1 hour per day at a volume control setting of ≥60% for ≥2 years were considered regular PMS users, while other participants were considered non-regular PMS users. A custom-made questionnaire with a total of 24 questions was administered to all participants.ResultsStatistical analysis indicated that the occurrence of symptoms such as reduced hearing and vertigo were significantly higher in regular PMS users than in non-regular users. However, other symptoms such as tinnitus, difficulty in perception of speech in noisy situations, ear pain, and headache were not significantly different between the groups.ConclusionsThe findings substantiate the harmful effects of regular PMS usage on hearing and related functions. They also document the incidence of associated symptoms.

Personal Audio Systems Unsafe At Any Sound

Personal Audio Systems Unsafe At Any Sound

Investigating Real-World Benefits of High-Frequency Gain in Bone-Anchored Users with Ecological Momentary Assessment and Real-Time Data Logging.

Purpose: To compare listening ability (speech reception thresholds) and real-life listening experience in users with a percutaneous bone conduction device (BCD) with two listening programs differing only in high-frequency gain. In situ real-life experiences were recorded with ecological momentary assessment (EMA) techniques combined with real-time acoustical data logging and standard retrospective questionnaires. Methods: Nineteen experienced BCD users participated in this study. They all used a Ponto 4 BCD from Oticon Medical during a 4-week trial period. Environmental data and device parameters (i.e., device usage and volume control) were logged in real-time on an iPhone via a custom iOS research app. At the end of the trial period, subjects filled in APHAB, SSQ, and preference questionnaires. Listening abilities with the two programs were evaluated with speech reception threshold tests. Results: The APHAB and SSQ questionnaires did not reveal any differences between the two listening programs. The EMAs revealed group-level effects, indicating that in speech and noisy listening environments, subjects preferred the default listening program, and found the program with additional high-frequency gain too loud. This finding was corroborated by the volume log—subjects avoided the higher volume control setting and reacted more to changes in environmental sound pressure levels when using the high-frequency gain program. Finally, day-to-day changes in EMAs revealed acclimatization effects in the listening experience for ratings of “sound quality” and “program suitability” of the BCD, but not for ratings of “loudness perception” and “speech understanding”. The acclimatization effect did not differ among the listening programs. Conclusion: Adding custom high-frequency amplification to the BCD target-gain prescription improves speech reception in laboratory tests under quiet conditions, but results in poorer real-life listening experiences due to loudness.

Adaptive support ventilation attenuates postpneumonectomy acute lung injury in a porcine model.

An optimal ventilation strategy that causes as little mechanical stress and inflammation as possible is critical for patients undergoing pneumonectomy. The aim of this study was to determine whether adaptive support ventilation (ASV) can provide protective ventilation to the remaining lung after pneumonectomy with minimal mechanical stress and less inflammation than volume-control ventilation (VCV). In this study, 15 pigs were randomly allocated to 3 groups (n = 5 for each group): the control group, the VCV group and the ASV group. After left pneumonectomy, the VCV group was treated with the volume-control set to 20 ml/kg, and the ASV group with the mode set to achieve 60% of the minute ventilation of 2 lungs. The ASV group had lower alveolar strain than the VCV group. The ASV group exhibited less lung injury and greater alveolar fluid clearance than the VCV group (13.3% vs -17.8%; P ≤ 0.018). Ventilator-induced lung injury was associated with changes in the cytokine levels in the exhaled breath condensate, differential changes in plasma and changes in the cytokines in the bronchoalveolar lavage fluid. Expression of 3 microRNAs (miR449b-3p, P ≤ 0.001; miR451-5p, P = 0.027; and miR144-5p, P = 0.008) was increased in the VCV group compared with the ASV group. The ASV mode was capable of supporting rapid, shallow breathing patterns to exert lung-protective effects in a porcine postpneumonectomy model. Further investigation of microRNAs as biomarkers of ventilator-induced lung injury is warranted.

Comparisons of Metabolic Load between Adaptive Support Ventilation and Pressure Support Ventilation in Mechanically Ventilated ICU Patients.

Purpose The aim of this study was to compare the metabolic load between adaptive support ventilation (ASV) and pressure support ventilation (PSV) modes in critically ill patients. Methods Sequential 20 min ventilation by PSV followed by 20 min ASV in critically ill patients was assessed. ASV was set for full support, i.e., with the minute volume control set at the same level as the minute volume observed during PSV. The trial started from PSV 8 cmH2O and continued with high (PSV 12 cmH2O) to low (PSV 0) conditions or low to high conditions, in random order. The oxygen consumption (VO2), production of carbon dioxide (VCO2), and energy expenditure (EE) were measured by indirect calorimetry (IC). Results Twenty-four patients with critical illness participated in the study. Comparing with the PSV mode, the EE in the ASV mode was lower in the level of PSV 0 cmH2O (1069 ± 73 vs. 1425 ± 76 kcal), PS 8 cmH2O (1116 ± 70 vs. 1284 ± 61 kcal), and PS 12 cmH2O (1017 ± 70 vs. 1169 ± 58 kcal) (p < 0.05). The VO2, VCO2, and P0.1 in PSV were significantly higher than those in ASV (p < 0.05). The VO2, VCO2, and P0.1 in PSV were significantly higher than those in ASV (Conclusion In patients with critical illness, the application of ASV set for full support was associated with a lower metabolic load and respiratory drive than in any of the studied PSV conditions.

Fibromyalgia

Clinicians often encounter individuals who present with pain that they cannot adequately explain based on the degree of damage or inflammation noted in peripheral tissues. This typically prompts an evaluation looking for a cause of the pain. If no cause is found, these individuals are often given a diagnostic label that merely connotes that the patient has chronic pain in a region of the body, without an underlying mechanistic cause. Fibromyalgia (FM) is merely the current term for widespread musculoskeletal pain for which no alternative cause can be identified. This review covers the epidemiology, etiology/genetics, pathophysiology and pathogenesis, diagnosis, differential diagnosis, treatment, and complications and prognosis of FM. Figures show underlying mechanisms that can cause chronic pain; an individual’s “set point” or “volume control setting” for pain as set by a variety of factors, including the levels of neurotransmitters that either facilitate pain or reduce pain transmission; the 2011 Fibromyalgia Survey Criteria; symptoms and syndromes frequently seen in individuals with FM; the distribution of the 2011 Fibromyalgia Survey scores in a large cohort of individuals undergoing joint replacement surgery; and an algorithm showing the importance of dually focused treatment for FM and other chronic pain conditions. Tables list clinical characteristics of centralized pain, pharmacologic therapies for FM, and nonpharmacologic therapies for FM. This review contains 6 figures, 9 tables, and 78 references. Keywords: Fibromyalgia, chronic low back pain, headache, temporomandibular joint disorder, gastrointestinal disorder, irritable bowel syndrome (IBS), nonulcer dyspepsia, or esophageal dysmotility, interstitial cystitis, chronic prostatitis, vulvodynia, vulvar vestibulitis, and endometriosis

Fibromyalgia

Clinicians often encounter individuals who present with pain that they cannot adequately explain based on the degree of damage or inflammation noted in peripheral tissues. This typically prompts an evaluation looking for a cause of the pain. If no cause is found, these individuals are often given a diagnostic label that merely connotes that the patient has chronic pain in a region of the body, without an underlying mechanistic cause. Fibromyalgia (FM) is merely the current term for widespread musculoskeletal pain for which no alternative cause can be identified. This review covers the epidemiology, etiology/genetics, pathophysiology and pathogenesis, diagnosis, differential diagnosis, treatment, and complications and prognosis of FM. Figures show underlying mechanisms that can cause chronic pain; an individual’s “set point” or “volume control setting” for pain as set by a variety of factors, including the levels of neurotransmitters that either facilitate pain or reduce pain transmission; the 2011 Fibromyalgia Survey Criteria; symptoms and syndromes frequently seen in individuals with FM; the distribution of the 2011 Fibromyalgia Survey scores in a large cohort of individuals undergoing joint replacement surgery; and an algorithm showing the importance of dually focused treatment for FM and other chronic pain conditions. Tables list clinical characteristics of centralized pain, pharmacologic therapies for FM, and nonpharmacologic therapies for FM. This review contains 6 figures, 9 tables, and 78 references. Keywords: Fibromyalgia, chronic low back pain, headache, temporomandibular joint disorder, gastrointestinal disorder, irritable bowel syndrome (IBS), nonulcer dyspepsia, or esophageal dysmotility, interstitial cystitis, chronic prostatitis, vulvodynia, vulvar vestibulitis, and endometriosis

Fibromyalgia

Clinicians often encounter individuals who present with pain that they cannot adequately explain based on the degree of damage or inflammation noted in peripheral tissues. This typically prompts an evaluation looking for a cause of the pain. If no cause is found, these individuals are often given a diagnostic label that merely connotes that the patient has chronic pain in a region of the body, without an underlying mechanistic cause. Fibromyalgia (FM) is merely the current term for widespread musculoskeletal pain for which no alternative cause can be identified. This review covers the epidemiology, etiology/genetics, pathophysiology and pathogenesis, diagnosis, differential diagnosis, treatment, and complications and prognosis of FM. Figures show underlying mechanisms that can cause chronic pain; an individual’s “set point” or “volume control setting” for pain as set by a variety of factors, including the levels of neurotransmitters that either facilitate pain or reduce pain transmission; the 2011 Fibromyalgia Survey Criteria; symptoms and syndromes frequently seen in individuals with FM; the distribution of the 2011 Fibromyalgia Survey scores in a large cohort of individuals undergoing joint replacement surgery; and an algorithm showing the importance of dually focused treatment for FM and other chronic pain conditions. Tables list clinical characteristics of centralized pain, pharmacologic therapies for FM, and nonpharmacologic therapies for FM. This review contains 6 figures, 9 tables, and 78 references. Keywords: Fibromyalgia, chronic low back pain, headache, temporomandibular joint disorder, gastrointestinal disorder, irritable bowel syndrome (IBS), nonulcer dyspepsia, or esophageal dysmotility, interstitial cystitis, chronic prostatitis, vulvodynia, vulvar vestibulitis, and endometriosis

Risk Assessment of Recreational Noise-Induced Hearing Loss from Exposure through a Personal Audio System-iPod Touch.

Recreational noise-induced hearing loss (RNIHL) is a major health issue and presents a huge economic burden on society. Exposure to loud music is not considered hazardous in our society because music is thought to be a source of relaxation and entertainment. However, there is evidence that regardless of the sound source, frequent exposure to loud music, including through personal audio systems (PAS), can lead to hearing loss, tinnitus, difficulty processing speech, and increased susceptibility to age-related hearing loss. Several studies have documented temporary threshold shifts (TTS) (a risk indicator of future permanent impairment) in subjects that listen to loud music through their PAS. However, there is not enough information regarding volume settings that may be considered to be safe. As a primary step toward quantifying the risk of RNIHL through PAS, we assessed changes in auditory test measures before and after exposure to music through the popular iPod Touch device set at various volume levels. This project design incorporated aspects of both between- and within-subjects and used repeated measures to analyze individual groups. A total of 40 adults, aged 18-31 years with normal hearing were recruited and randomly distributed to four groups. Each group consisted of five males and five females. Subjects underwent two rounds of testing (pre- and postmusic exposure), with a 30-min interval, where they listened to a playlist consisting of popular songs through an iPod at 100%, 75%, 50%, or 0% volume (no music). Based on our analysis on the Knowles Electronic Manikin for Acoustic Research, with a standardized 711 coupler, it was determined that listening to the playlist for 30 min through standard earbuds resulted in an average level of 97.0 dBC at 100% volume, 83.3 dBC at 75% volume, and 65.6 dBC at 50% volume. Pure-tone thresholds from 500-8000 Hz, extended high-frequency pure tones between 9-12.5 kHz, and distortion product otoacoustic emissions (DPOAE) were obtained before and after the 30-min music exposure. Analysis of variance (ANOVA) was performed with two between-subjects factors (volume and gender) and one within-subjects factor (frequency). Change (shift) in auditory test measures was used as the outcome for the ANOVA. Results indicated significant worsening of pure-tone thresholds following music exposure only in the group that was exposed to 100% volume at the following frequencies: 2, 3, 4, 6 and 8 kHz. DPOAEs showed significant decrease at 2000 and 2822 Hz, also only for the 100% volume condition. No significant changes were found between pre- and postmusic exposure measures in groups exposed to 75%, 50%, or 0% volume conditions. Follow-up evaluations conducted a week later indicated that pure-tone thresholds had returned to the premusic exposure levels. These results provide quantifiable information regarding safe volume control settings on the iPod Touch with standard earbuds. Listening to music using the iPod Touch at 100% volume setting for as little as 30 min leads to TTS and worsening of otoacoustic emissions, a risk for permanent auditory damage.

Listening to music with personal listening devices: monitoring the noise dose using a smartphone application

Objectives. To monitor listening habits to personal listening devices (PLDs) using a smartphone application and to compare actual listening habits to self-report data. Design. Two stages: self-report listening habits questionnaire, and real-time monitoring of listening habits through a smartphone application. Study sample. Overall 117 participants aged 18–34 years (mean 25.5 years) completed the questionnaire, and of them, 40 participants (mean age: 25.2 years) were monitored for listening habits during two weeks. Results. Questionnaire main findings indicated that most of the participants reported listening for 4–7 days a week, for at least 30 min at high listening levels with volume control settings at 75–100%. Monitored data showed that actual listening days per week were 1.5–6.5 d, with mean continuous time of 1.56 h, and mean volume control setting of 7.39 (on a scale of 1–15). Eight participants (22%) were found to exceed the 100% noise dose at least once during the monitoring period. One participant (2.7%) exceeded the weekly 100% daily noise dose. Correlations between actual measurements and self-report data were low to moderate. Conclusions. Results confirmed the feasibility of monitoring listening habits by a smartphone application, and underscore the need for such a tool to enable safe listening behaviour.

Physical Incompatibility between Parenteral Cloxacillin and Vancomycin

Cloxacillin sodium is a s -lactam antibiotic commonly used to treat gram-positive infections, especially those caused by Staphylococcus aureus. Cloxacillin may be administered as an infusion prepared in 0.9% sodium chloride (normal saline [NS]), 5% dextrose in water, or lactated Ringer’s solution. Along with cloxacillin, patients may be receiving other drugs by simultaneous or sequential Y-site administration, including other glycopeptide antibiotics such as vancomycin hydrochlor ide. In clinical practice, cloxacillin and vancomycin have been initiated concurrently as empiric therapy while awaiting the results of organism identification and sensitivity testing. As well, in vitro synergy with the combination of glycopeptides and s -lactams has been described in clinical isolates of vancomycin-susceptible, methicillin-resistant S. aureus, hetero geneous glycopeptide intermediate resistant S. aureus, and glycopeptide-intermediate S. aureus. 1-3 No compatibility information for administering cloxacillin simultaneously or sequentially with vancomycin has been published. 4 This study was initiated after a nurse at the authors’ institution reported formation of a gel-like substance in the polyvinyl chloride (PVC) IV volume-control set and line. The observation was made during administration of cloxacillin and vancomycin sequentially through a Y-site connector (separated by NS flush). The drugs were being given for empiric treatment of infective endocarditis while awaiting results of sensitivity testing of S. aureus. The purpose of this study was to determine the physical compatibility of cloxacillin diluted for infusion with vancomycin during simulated Y-site administration, as assessed by visual observation.

Comparison of User Volume Control Settings for Portable Music Players with Three Earphone Configurations in Quiet and Noisy Environments

Listening to music is one of the most common forms of recreational noise exposure. Previous investigators have demonstrated that maximum output levels from headphones can exceed safe levels. Although preferred listening levels (PLL) in quiet environments may be at acceptable levels, the addition of background noise will add to the overall noise exposure of a listener. Use of listening devices that block out some of the background noise would potentially allow listeners to select lower PLLs for their music. Although one solution is in-the-ear earphones, an alternative solution is the use of earmuffs in conjunction with earbuds. There were two objectives to this experiment. The first was to determine if an alternative to in-the-ear earphones for noise attenuation (the addition of earmuffs to earbuds) would allow for lower PLLs through a portable media player (PMP) than earbuds. The second was to determine if a surrounding background noise would yield different PLLs than a directional noise source. This was an experimental study. Twenty-four adults with normal hearing. PLLs were measured for three earphone configurations in three listening conditions. The earphone configurations included earbuds, canal earphones, and earbuds in combination with hearing protection devices (HPDs). The listening conditions included quiet, noise from one loudspeaker, and noise from four surrounding loudspeakers. Participants listened in each noise and earphone combination for as long as they needed to determine their PLL for that condition. Once the participant determined their PLL, investigators made a 5 sec recording of the music through a probe tube microphone. The average PLLs in each noise and earphone combination were used as the dependent variable. Ear canal level PLLs were converted to free-field equivalents to compare to noise exposure standards and previously published data. The average PLL as measured in the ear canal was 74 dBA in the quiet conditions and 84 dBA in the noise conditions. Paired comparisons of the PLL in the presence of background noise for each pair of earphone configurations indicated significant differences for each comparison. An inverse relationship was observed between attenuation and PLL whereby the greater the attenuation, the lower the PLL. A comparison of the single noise source condition versus the surrounding noise condition did not result in a significant effect. The present work suggests that earphones that take advantage of noise attenuation can reduce the level at which listeners set music in the presence of background noise. An alternative to in-the-ear earphones for noise attenuation is the addition of earmuffs to earbuds.

Comparison of Speech Intelligibility Measures for An Electronic Amplifying Earmuff and An Identical Passive Attenuation Device

The purpose of this study was to identify any differences between speech intelligibility measures obtained with MineEars electronic earmuffs (ProEars, Westcliffe, CO, USA) and the Bilsom model 847 (Sperian Hearing Protection, San Diego, CA, USA), which is a conventional passive-attenuation earmuff. These two devices are closely related, since the MineEars device consisted of a Bilsom 847 earmuff with the addition of electronic amplification circuits. Intelligibility scores were obtained by conducting listening tests with 15 normal-hearing human subject volunteers wearing the earmuffs. The primary research objective was to determine whether speech understanding differs between the passive earmuffs and the electronic earmuffs (with the volume control set at three different positions) in a background of 90 dB(A) continuous noise. As expected, results showed that speech intelligibility increased with higher speech-to-noise ratios; however, the electronic earmuff with the volume control set at full-on performed worse than when it was set to off or the lowest on setting. This finding suggests that the maximum volume control setting for these electronic earmuffs may not provide any benefits in terms of increased speech intelligibility in the background noise condition that was tested. Other volume control settings would need to be evaluated for their ability to produce higher speech intelligibility scores. Additionally, since an extensive electro-acoustic evaluation of the electronic earmuff was not performed as a part of this study, the exact cause of the reduced intelligibility scores at full volume remains unknown.

Teenage Use of Portable Listening Devices: A Hazard to Hearing?

Recently, a number of popular media articles have raised some concern that portable listening devices (PLDs) may be increasing the risk for music-induced hearing loss (MIHL). However, literature regarding adolescents' listening behavior and how their attitudes and beliefs relate to behavior is currently limited. The purposes of this study were (1) to investigate the relationship between volume control settings and output levels of PLDs, (2) to examine how adolescents' listening behavior changes as a function of background noise and noise isolation, (3) to investigate the relationship between self-reported listening levels and laboratory-measured listening levels, and (4) to evaluate the validity of the Listening Habits Questionnaire as a research tool for evaluating how attitudes and beliefs relate to PLD use behavior. A descriptive study. Experiment 1 evaluated the output levels of a set of PLDs, and Experiment 2 characterized the listening behavior and attitudes toward PLD use of a group of adolescents. Twenty-nine adolescents aged 13-17 yr, with normal hearing, participated in Experiment 2. Experiment 1 evaluated the output levels of a set of PLDs with stock and accessory earphones using an acoustic manikin. Experiment 2 included survey measures of listening behavior and attitudes as well as output levels measured using a probe microphone. The output levels of PLDs are capable of reaching levels that could increase the risk for MIHL, and 14% of teenagers in this study reported behavior that puts them at increased risk for hearing loss. However, measured listening levels in the laboratory settings did not correlate well with self-reported typical listening levels. Further, the Listening Habits Questionnaire described in this study may provide a useful research tool for examining the relationship between attitudes and beliefs and listening behavior.

Knowledge Grows About Puzzling Disorder

Although a handful of medications and some nondrug regimens are used to treat fibromyalgia, even more effective treatments may be on the horizon.

Comparison of speech intelligibility measures for an electronic amplifying earmuff and an identical passive attenuation device.

The purpose of this study was to identify any differences between speech intelligibility measures obtained with MineEars electronic earmuffs (ProEars, Westcliffe, CO, USA) and the Bilsom model 847 (Sperian Hearing Protection, San Diego, CA, USA), which is a conventional passive-attenuation earmuff. These two devices are closely related, since the MineEars device consisted of a Bilsom 847 earmuff with the addition of electronic amplification circuits. Intelligibility scores were obtained by conducting listening tests with 15 normal-hearing human subject volunteers wearing the earmuffs. The primary research objective was to determine whether speech understanding differs between the passive earmuffs and the electronic earmuffs (with the volume control set at three different positions) in a background of 90 dB(A) continuous noise. As expected, results showed that speech intelligibility increased with higher speech-to-noise ratios; however, the electronic earmuff with the volume control set at full-on performed worse than when it was set to off or the lowest on setting. This finding suggests that the maximum volume control setting for these electronic earmuffs may not provide any benefits in terms of increased speech intelligibility in the background noise condition that was tested. Other volume control settings would need to be evaluated for their ability to produce higher speech intelligibility scores. Additionally, since an extensive electro-acoustic evaluation of the electronic earmuff was not performed as a part of this study, the exact cause of the reduced intelligibility scores at full volume remains unknown.

Personal Music Systems: Do They Pose Risk for Hearing Loss?

The proliferation of personal music systems in recent years raises concern because of the tremendous quantity of audio stimulation that users – especially children are exposed to. Hearing loss induced by personal music systems may evolve into a significant social and public health problem in future years. Currently, in our lab we are assessing the relationship among music listening habits of young adults, output sound pressure levels of different personal music systems and their effect on the auditory system, using behavioral and physiological measures. Our results show that about 66% of young adults listen to music using personal music systems for more than 1 hour a day. About 27% of these individuals report some kind of ontological problems. Measurement of output sound pressure levels of personal music system showed that about 20% of users listen to music at sufficiently high levels to cause permanent hearing loss. Pure tone audiogram and otoacoustic emissions revealed that listening to music through personal music system at preferred volume control settings did not result in “clinically significant” elevation of hearing thresholds or reduction of otoacoustic emissions amplitudes but caused subtle pre-clinical damage to the auditory system and over the years such behavior may be hazardous to hearing.

Comparison of loudness adjustments by MCL and maplaw in users of the MED-EL COMBI 40/40+ cochlear implant system

The programming of a CI speech processor involves measurement of electrical threshold and ‘most comfortable loudness’ (MCL) levels on each electrode. However, when the derived ‘map’ is activated the resultant percept is often too loud or too soft. In this situation, adjustments of MCL settings are usually made in order to achieve a comfortable percept.The present study examined the range of volume control adjustments in 24 users of the MED-EL C40/40+ device. Volume control settings varied from 36% to 126% with a mean of 84.3% (SD = 20.4%). Additionally, the output compression function (‘maplaw’) was adjusted to test whether this alternative manipulation could result in a comfortable percept. It was found that this could be achieved satisfactorily, with maplaw values ranging from 10 to 2000. Clinical implications of these findings are discussed. Copyright © 2009 John Wiley & Sons, Ltd.

Comparison of loudness adjustments by MCL and maplaw in users of the MED-EL COMBI 40/40+ cochlear implant system

The programming of a CI speech processor involves measurement of electrical threshold and 'most comfortable loudness' (MCL) levels on each electrode. However, when the derived 'map' is activated the resultant percept is often too loud or too soft. In this situation, adjustments of MCL settings are usually made in order to achieve a comfortable percept.The present study examined the range of volume control adjustments in 24 users of the MED-EL C40/40+ device. Volume control settings varied from 36% to 126% with a mean of 84.3% (SD = 20.4%). Additionally, the output compression function ('maplaw') was adjusted to test whether this alternative manipulation could result in a comfortable percept. It was found that this could be achieved satisfactorily, with maplaw values ranging from 10 to 2000. Clinical implications of these findings are discussed.