The potential risk to hearing that mass-storage personal listening devices ͑PLDs͒ 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 ͑2002͒, Switzerland; ISO 11904-2 ͑2004͒, Switzerland͔ for the measurement of preferred listening levels of PLD. Noise measurements, behavioral thresholds, and oral interviews were obtained from 30 ͑18-30 years͒ 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 ͑2002͒, Switzerland͔. 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.

Gender-based norms for auditory-evoked potentials measures are standard in clinical settings. The results of the present study, in agreement with previous studies, indicate that significant interactions exist between gender and DPOAE group delay values in the lower frequencies, and between gender and DPOAE levels at the higher frequencies. To reach the goal of using high frequency DPOAEs in clinical protocols, such as for auditory neuropathy/dys-synchrony diagnosis and ototoxicity monitoring, DPOAEs elicited with conventional and higher frequency stimuli must be understood, including the role of gender to determine if an effect on clinical protocols would exist.

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Idiopathic sudden sensorineural hearing loss (ISSNHL) refers to a loss of hearing, most commonly unilateral, that occurs suddenly (≤72 h) with no identifiable cause or etiology. To date, there is no standard protocol to predict prognosis (hearing recovery) for patients with ISSNHL. However, studies have shown that changes in otoacoustic emissions (OAEs) often occur prior to changes in audiometric hearing thresholds. OAEs originate from the electrochemical motility of the outer hair cells (OHC) and reflect the integrity of the inner ear, specifically the cochlear amplifier. Therefore, OAEs may be useful as a prognostic predictive factor in patients with ISSNHL from the initial onset of symptoms through recovery. A systematic review of the literature was undertaken to assess the relationship between pure tone thresholds, OAEs, and subjective hearing improvement and/or recovery. Fourteen studies were identified for inclusion, and they overwhelmingly support the inclusion of OAEs in the protocol to monitor ISSNHL recovery. This finding supports the development of a standard diagnostic protocol that includes OAEs to predict patient hearing outcomes.