Probe−tube microphone assembly

Villchur, Edgar; Killion, Mead C.

doi:10.1121/1.380431

Cited by 8 publications

(4 citation statements)

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“…The earphone was calibrated with a combination of measurements using a probe microphone (Villchur and Killion, 1975) and KEMAR (Burkhard and Sachs, 1975). This procedure, described in Footnote 2, was required because of the use of a nonstandard earphone cushion.…”

Section: Methodsmentioning

confidence: 99%

Potential benefits of adaptive frequency-gain characteristics for speech reception in noise

Rankovic

Freyman

Zurek

1992

The Journal of the Acoustical Society of America

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Some current single-microphone hearing aids employ techniques for adaptively varying the frequency-gain characteristics in an attempt to improve speech reception in noise. The potential benefit of this strategy depends on the spectral spread of masking and the degree to which it can be reduced by changing the frequency-gain characteristic. In this study these benefits were examined for subjects with normal hearing under static listening conditions. In the unprocessed condition, subjects were presented with nonsense syllables in an octave-band noise centered on 0.5, 1, or 2 kHz. The frequency-gain characteristic was then modified with the goal of reducing the intensity of the frequency region containing the octave-band noise. This processing resulted in increases as large as 60 percentage points in consonant-correct scores with the low- and mid-frequency octave noise bands, and a small increase with the high-frequency noise. Masking patterns produced by the octave noises were also measured and were related to the intelligibility results via an analysis based on Articulation Theory. The Articulation Index was also used to compare the effectiveness of three adaptive rules. A simple multiband volume control is expected to provide much of the benefit of more sophisticated systems without the need for separate estimation of input speech and noise spectra.

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Section: Methodsmentioning

confidence: 99%

Potential benefits of adaptive frequency-gain characteristics for speech reception in noise

Rankovic

Freyman

Zurek

1992

The Journal of the Acoustical Society of America

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“…The subjects listened binaurally to the stimuli over Sennheiser HD-430 headphones in a sound-treated room. Headphones were calibrated using a probe-microphone calibration technique [13]. For the 'within-band' experiments, subjects were free at the onset of each experiment to adjust the volume on the tape deck to a comfortable level as long as the adjustment would not result in sound levels exceeding 90 dB SPL.…”

Section: Experimental Paradigmmentioning

confidence: 99%

A perceptual metric for masking

Alwan¹

1993

IEEE International Conference on Acoustics Speech and Signal Processing

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In this study, analytical tools were developed to predict masking of formant frequencies of steady-state vowels in the presence of a noise masker. Two kinds of masking were studied: within-band masking (where the signal frequency was within the bandwidth of a noise masker) and above-band masking (where the signal frequency was above the upper cutoff frequency of the masker.) It was found that results of auditory-masking theory can be used to accurately predict within-band masking. Above-band masking, however, could not be predicted well from existing procedures and an algorithm was developed to predict this kind of masking.

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“…In order to capture the HRTFs at a point very close to the eardrum, the measurement needs to be done using a probe, or a probe tube, microphone that is introduced very close to the eardrum. 1 This kind of measurement is unpleasant and risky from the subject's point of view. In addition, it is difficult to fix the probe microphone close enough to the eardrum without the risk of touching it.…”

Section: Introductionmentioning

confidence: 99%

Estimating head-related transfer functions of human subjects from pressure–velocity measurements

Hiipakka

Kinnari

Pulkki

2012

The Journal of the Acoustical Society of America

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Direct measurements of individual head-related transfer functions (HRTFs) with a probe microphone at the eardrum are unpleasant, risky, and unreliable and therefore have not been widely used. Instead, the HRTFs are commonly measured from the blocked ear canal entrance, which excludes the effects of the individual ear canals and eardrums. This paper presents a method that allows obtaining individually correct magnitude frequency responses of HRTFs at the eardrum from pressure-velocity (PU) measurements at the ear canal entrance with a miniature PU sensor. The HRTFs of 25 test subjects with nine directions of sound incidence were estimated using real anechoic measurements and an energy-based estimation method. To validate the approach, measurements were also conducted with probe microphones near the eardrums as well as at blocked ear canal entrances. Comparisons between the different methods show that the method presented is a valid and reliable technique for obtaining magnitude frequency responses of HRTFs. The HRTF filters designed using the PU measurements are also shown to yield more correct frequency responses at the eardrum than the filters designed using measurements from the blocked ear canal entrance.

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Probe−tube microphone assembly

Abstract: A method of making in-the-ear probe-microphone measurements is described, using readily available equipment. The procedure is designed to make such measurements easier and safer than they have been in the past.Subject Classification: 85.62; 65.80.

Cited by 8 publications

References 0 publications

Potential benefits of adaptive frequency-gain characteristics for speech reception in noise

Potential benefits of adaptive frequency-gain characteristics for speech reception in noise

A perceptual metric for masking

Estimating head-related transfer functions of human subjects from pressure–velocity measurements

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