Playback Techniques Research Articles

Review of the High-Frequency Playback Limits of Mechanically Recorded Disks

The extension of the upper frequency limit of the playback stylus is reviewed from a theoretical and measured review of the published work of C. R. Bastaians and subsequent additional data presented by J. White. From these apparent limits the discussion of the newly introduced high-frequency playback techniques developed at Teldec are reviewed. [C. R. Bastiaans, “Factors Affecting the Stylus/Groove Relationship in Phonograph Playback Systems,” J. Audio Eng. Soc. 15, 389–399 (October 1967); Offenlegungsschrift 1 574 489, German Patent Office, 10 September 1970).]

Influence of Playback Techniques on Counselor Preformance

Study was made of training impact of different electronic playback techniques on ratings of student counselor performance. Thirty-two upperclass university females were randomly divided into four playback treatment groups: (a) audio-video, (b) audio, (c) video, and (d) no playback received. Four underclass university females served as trained clients. All student counselors interviewed two different trained clients in two 20-minute sessions separated by a playback treatment period. All sessions were recorded by television cameras. Trained judges rated the second interview using the Counselor Evaluation Inventory, Nonverbal Behavior Scale, and Audio-Visual Counseling Scale. Two-way analysis of variance was used to compare scores on criterion instruments. Results indicated no judged differences among the playback treatment groups, nor could discriminant rankings be made among the various playback methods. Several explanations are discussed as to limited influence of playback media on early interview performance.

A Note on Normal Incidence Reflections from the Mohorovi i Discontinuity

Summary Very approximate calculations are made of the expected amplitude and frequency of seismic pulses reflected from the Mohoroviciȳ discontinuity. In deep oceans the effect of layer 2 is all important, as multiples generated within it may obscure any Moho reflection. In both land and oceanic areas charges of at least 100 Ib of explosive will be necessary to raise any Moho reflection above ambient background noise and particular care will have to be taken to eliminate shot-generated noise. It is most desirable to record on magnetic tape so that optimum playback techniques may be used to maximize the signal-to-noise ratio.

Electro-Sonic Profiler: ABSTRACT

The Rayflex Electro-Sonic Profiler was developed for petroleum exploration in 1961. The general objectives of its development were to provide marine seismic information in greater clarity and detail than previous methods at modest costs. Initially a tool for shallow depths, the Electro-Sonic Profiler has through use and further engineering become capable of revealing detail at production levels. In addition, its application to deep-water oceanography has advanced the study of the oceanic province by many years. Present use of the Electro-Sonic Profiler has shown numerous types of geological events in near text book quality. Compositing and playback techniques have expanded capabilities towards the deep look-see. Interpretation problems are minimized through use of special recording techniques. Numerous marine profiles demonstrate the flexibility and usefulness of the method. End_of_Article - Last_Page 1765------------