In-the-ear calibration of sound pressure level may be problematic at frequencies above 2 kHz, because the pressure can vary significantly along the length of the ear canal, due to reflection of sound waves at the eardrum. This issue has been investigated by measuring behavioral thresholds to tones in a group of human subjects (N = 61) for two different insertion depths of an insert earphone. Th...

The influence of fatiguing sound level and duration on post-exposure temporary threshold shift (TTS) was investigated in two beluga whales (Delphinapterus leucas). The fatiguing sound was half-octave noise with a center frequency of 22.5 kHz. TTS was measured at a test frequency of 32 kHz. Thresholds were measured by recording rhythmic evoked potentials (the envelope following response) to a te...

Sound field reconstruction using the least-square method is employed in sound reinforcement applications to achieve uniform sound pressure level (SPL) over audience area in this study. A practical problem that the radiated sound energy decline in audience area appears at low frequencies with conventional least-square method. An approach based on energy contrast control is devised to solve this ...

Aerodynamic bogie noise was quantitatively estimated at a wayside observation point by using spatial distribution of the sound pressure level (SPL) obtained two-dimensional microphone array in wind tunnel test. In order to evaluate SPL, it is necessary appropriately consider generation and field with respect various acoustic properties such as ground reflection insertion loss side cover. this s...

The tolerability of aided impulsive-type stimuli was investigated in a group of 13 hearing-impaired listeners. Two linear circuits (one with a class A and one with a class D output stage) and one adaptive frequency response (AFR) circuit (with a class D output stage) were investigated. In a three-way paired-comparison task, subjects chose the hearing aid that was most tolerable when 75 dB sound...

Measures of the sound pressure level (SPL) near the eardrum were determined at discrete frequencies between 500 and 4000 Hz on 50 ears using TDH-39P and ER-3A earphones with the attenuator of an audiometer fixed at 90 dB HL. Results revealed significant differences in the measured SPL between the two earphones at all test frequencies. Results also revealed large intersubject differences in the ...

abstract- noise is considered as one of the most debilitating conditions in farming operations. in this study, a number of factors affecting the noise generated by sampo 3065 combine harvesters were evaluated. factors were engine speed and gear ratio for combines with and without original cabins. a factorial experiment arranged as a completely randomized design with four replicates was used. re...

Real-ear measurements of the aided Loudness Discomfort Level (LDL) were obtained from five hearing-impaired listeners who were fit with two Class A and two Class D linear hearing aids, each with a different saturation sound pressure level (HFA SSPL90). These measurements were obtained with 75 dB SPL continuous discourse to determine whether saturation-induced distortion contributes to the sensa...