摘要:

The author clarifies and corrects his recent article.

ISSN:0001-4966    

DOI:10.1121/1.421105

出版商:Acoustical Society of America    

年代:1998

数据来源: AIP

摘要:

A heuristic model is presented which quantifies the effect of a compressive residual stress of the dispersion on a Rayleigh wave propagating over a cracked surface. The model shows that a residual stress acting on the outermost part of a surface, and extending for about 20% of the crack depth within the sample, reduces the dispersion of the Rayleigh wave by about 70%.

ISSN:0001-4966    

DOI:10.1121/1.421131

出版商:Acoustical Society of America    

年代:1998

数据来源: AIP

摘要:

The antisymmetrical Scholte–Stoneley wave in liquid-loaded metal and polymer membranes were excited via the laser-induced thermoelastic effect and were detected with a laser beam deflection technique. The experimentally determined dispersion relation for this wave is in accordance with theory in a wide frequency range. However, no evidence of the propagating subsonic lowest-order anitsymmetrical pseudo-Lamb wave was found.

ISSN:0001-4966    

DOI:10.1121/1.421132

出版商:Acoustical Society of America    

年代:1998

数据来源: AIP

摘要:

Very low power electromagnetic (EM) wave sensors are being used to measure speech articulator motions as speech is produced. Glottal tissue oscillations, jaw, tongue, soft palate, and other organs have been measured. Previously, microwave imaging (e.g., using radar sensors) appears not to have been considered for such monitoring. Glottal tissue movements detected by radar sensors correlate well with those obtained by established laboratory techniques, and have been used to estimate a voiced excitation function for speech processing applications. The noninvasive access, coupled with the small size, low power, and high resolution of these new sensors, permit promising research and development applications in speech production, communication disorders, speech recognition and related topics.

ISSN:0001-4966    

DOI:10.1121/1.421133

出版商:Acoustical Society of America    

年代:1998

数据来源: AIP

摘要:

Steady-state line spectra of the C’s (C2 to C9) of eight diapasons of the Newberry Memorial organ were investigated using DAT records made in the hall. To better represent what a listener hears, the SPL spectra were transformed to loudness levels (LL’s), and adjusted to accommodate masking between the harmonics. The way the LL transformation altered the levels of the harmonics was shown in detail for C2, C4, and C6. The transformed LL spectral envelopes had essentially identical and well-known “diapason type” contours from C4 to C6. These envelopes differed from those at C2, C3 and C7, C8, and C9. Hence, no common diapason pattern was found over the entire frequency range. However, the spectral envelopes of the seven diapason at C2, for example, were similar, and constituted the “typical diapason” envelope at C2. The advisability of assuming a “typical diapason envelope” for all diapason sounds was discussed. The spectral envelopes at C7 and C8 of the diapason and also of chorus reed stops of the organ were similar. Since diapason type pipes were used for C7 and C8 of the reed stops (as is typical) it is not surprising that they sound similar to these notes of diapason stops.

ISSN:0001-4966    

DOI:10.1121/1.421134

出版商:Acoustical Society of America    

年代:1998

数据来源: AIP