Emil L. Torick

Measurements of diffraction and interaural delay of a progressive sound wave caused by the human head. II

A decade ago, two of the authors presented a paper reporting on diffraction and interaural delay of a progressive wave caused by the human head [J. Acoust. Soc. Am. 36, 1993(A) (1964)]. Six live subjects were used in those experiments. The publication was delayed pending measurements on artificial heads then being planned. In this paper, two series of data obtained with the aid of the Acoustical Manikin [J. Acoust. Soc. Am. 42, 204–207 (1967)] are compared with the earlier experiments: (a) Data based on phase measurements; (b) Data obtained using a bandwidth‐limited delta pulse. All three methods provide useful information about interaural diffraction and delay, albeit the third method appears to be the most reliable.

FM Receivers in Automobiles: a Case for Deiversity Reception

The inconsistent quality of FM reception in automobiles is a major impediment to the well-deserved growth of this important medium. Although FM inherently has the potential for high- fidelity performance and has become a significant competitor to AM broad- casting to the home, it cannot hope to achieve full parity with AM until it can also successfully reach the auto- mobile audience. This is not likely to happen as long as FM reception in autos is handicapped by the phenomenon of multipath distortion.

Experimental study of vibration and radiation characteristics of a violin

A study of a violins vibration and radiation characteristics has been undertaken using two techniques. The goals of the study are to perform a modal analysis of the instrument and to use the nearfield acoustical holography (NAH) system located at the Pennsylvania State University to reconstruct the instruments radiated sound field. The modal analysis will locate the various resonances of the top and back plates and show the relative motion of the plates. The NAH system will locate those areas on the instrument that produce the energy that radiates to the farfield. This paper will discuss the work completed to date and present the results obtained from this work.

Quadraphonic Broadcasting Using the SQ®System

Broadcast standards for transmission of the SQ matrix program are reviewed. Considerations of mono-stereo compatibility and broadcast coverage are analyzed, in comparison with performance of proposed discrete systems.

The Direct Measurement of Loudness Levels of Complex Sounds

Sixteen typical 1‐sec sound segments from a broadcast program, including speech, music, and noises were measured with a loudness level monitor [IEEE Trans. Audio Electroacoust. AU‐15, 178–182 (1967)] and with a sound level meter using A‐, B‐, and C‐weighting networks. The actual loudness levels of the 16 sounds were determined by loudness balance against a 1000‐Hz centered 13‐oct band of noise. The mean absolute deviation of the loudness level monitor readings from the actual loudness levels was 1.1 phons. The mean absolute deviations for the sound level meter were, for A‐weighting, 9.1 and 5.7 dB; for B‐weighting, 8.4 and 4.8 dB; and for C‐weighting, 5.8 and 3.2 dB, for the slow and fast meter settings, respectively.