Real-ear attenuation at threshold (REAT) and monaural pure-tone thresholds were determined for normally hearing adults using a supra-aural, Audiocup, and insert earphone. The thresholds were obtained in quiet and in background noises approximating the maximum permissible ambient noise levels (MPANLs) allowed in an audiometric test room specified by ANSI S3.1-1991 and OSHA (1983). The supra-aura...

BACKGROUND Although previous studies have reported that frequent earphone use and lead exposure are risk factors for hearing loss, most of these studies were limited to small populations or animal experiments. Several studies that presented the joint effect of combined exposure of noise and heavy metal on hearing loss were also mainly conducted on occupational workers exposed to high concentrat...

Reference equivalent threshold sound pressure levels (RETSPLs) were determined for 20 subjects for pure tones and 1/3-oct noise bands. Two transducers were used: a Telephonics TDH-49 earphone mounted in an MX-41/AR cushion, and a Danavox SMW insert earphone coupled to an "HA-2" earmold. RETSPLs for pure tones transduced by the TDH-49 earphone were very similar to those published previously. For...

In clinical measurements of hearing sensitivity, a given earphone is assumed to produce essentially the same sound-pressure level in all ears. However, recent measurements [Voss et al., Ear and Hearing (in press)] show that with some middle-ear pathologies, ear-canal sound pressures can deviate by as much as 35 dB from the normal-ear value; the deviations depend on the earphone, the middle-ear ...

Flexible microphone and earphone prototypes for wearable applications were developed by using ElectroMechanical Film (EMFi). A suitable application for the developed headset can be, for instance, as accessory of rescue services or sport enthusiasts. Due its versatile properties, EMFi can be used both as microphone and earphone material. The sensor operation is based on thickness changes caused ...

A new procedure is examined for psychoacoustic calibration of earphones in which the air-conducted outputs of a standard and an unknown earphone are successively equated for loudness to a reference boneconducted tone. The problem to the subject is one of monaural loudness discrimination, with a relatively small variance (differential sensitivity — 1.23 —1.61 dB), and involves only four sources ...

A new procedure is examined for psychoacoustic calibration of earphones in which the air-conducted outputs of a standard and an unknown earphone are successively equated for loudness to a reference boneconducted tone. The problem to the subject is one of monaural loudness discrimination, with a relatively small variance (differential sensitivity — 1.23 —1.61 dB), and involves only four sources ...

Nonlinearities in the cochlea can introduce audio frequencies that are not present in the sound signal entering the ear. Known as distortion products (DPs), these added frequencies complicate the interpretation of auditory experiments. Sound production systems also introduce distortion via nonlinearities, a particular concern for fMRI research because the Sensimetrics earphones widely used for ...

In 1933 data were reported which indicated that thresholds of hearing for frequencies apparently depended upon whether the source was an earphone (MAP) or a loudspeaker (MAF). A decade or so later the same type of discrepancy appeared when loudness balances were made at 100 Hz between an earphone source and a loudspeaker source. In both cases approximately 6 dB more sound pressure level at the ...

Auditory brainstem response (ABR) absolute thresholds were obtained from 31 ears of 28 newborns using both the insert and the earphone methods to deliver the stimuli. The two estimates on each ear were acquired in a single test session, and they differed by 10 dB or less in all cases. The results suggest that when the earphone is used, it rarely if ever collapses the ear canal to cause an artif...