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CONTENTS |
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xv |
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CHAPTER |
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PAGE |
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3. |
Signal Sound Level .......................... |
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466 |
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4. |
Ambient Noise Level ......................... |
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467 |
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5. |
Signal or Program Material |
................... |
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467 |
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6. |
Reference |
Systems |
.......................... |
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. |
467 |
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7. |
Relative |
Loudness |
Efficiency ............. |
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. .... |
468 |
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8. |
Relative |
Directivity ................. |
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. ........ |
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468 |
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9. |
Frequency Range |
............................ |
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468 |
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10. |
Power Handling Capacity ....... . .... . . . . . . . .. |
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468 |
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11. |
Response Frequency ..................Contour |
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469 |
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12. |
Nonlinear |
Distortion .. . ................... .. . |
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469 |
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13. |
Transient |
Response .......................... |
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469 |
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14. |
General |
Aspects ............................. |
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470 |
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10.4 |
TESTING OF TELEPHONE RECEIVERS .. .. .... .. ..• |
••• |
• |
••• |
•• |
470 |
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A. Subjective |
Measurements ..................... . ... |
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470 |
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B. Objective |
Measurements .......................... |
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471 |
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1. |
Artificial |
Ear ................................ |
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471 |
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2. |
Artificial |
Mastoid ............................ |
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472 |
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10.5 |
TESTING OF PHONOGRAPHS .•• .. ...... ....... ....... • |
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••• |
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472 |
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A. Measurement of the Response of a Phonograph Record |
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by the Optical |
Method ............................ |
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472 |
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B. Testing of Phonograph ....................Pickups |
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473 |
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C. Testing of Mechanical Phonographs ................ |
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475 |
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D. Measurement of Mechanical Noise Produced by a |
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Phonograph |
Pickup .............................. |
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475 |
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10.6 |
MEASUREMENT OF WOWS ........ ... ... ...... ... .. |
• |
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•• |
475 |
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10.7 |
MEASUREMENT OF ACOUSTICAL ..... ..IMPEDANCE |
.••.• |
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• •• |
476 |
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10.8MEASUREMENT OF MECHANICAL IMPEDANCE ••.•.•.••.•••. 478
10.9 |
MEASUREMENT |
OF POROSITY |
.•••• • .••••..... |
• ••.••.. |
•••• |
484 |
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1O.l0 |
MEASUREMENT OF D.C. ACOUSTICAL RESISTANCE (FLOW |
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RESISTANCE) |
• |
.. •••.••.•...•.... |
•.•... |
••.. |
•••.. |
•••••••• |
485 |
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1O.l1 |
MEASUREMENT OF REVERBERATION TIME •..... |
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•••..... |
•.• |
486 |
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10.l2 |
MEASUREMENT OF ABSORPTION COEFFICIENT |
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487 |
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10.l3 |
MEASUREMENT OF NOISE ••........... |
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•.•.••• |
.... |
•... |
••• |
488 |
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1O.l4 |
MEASUREMENT OF THE COMPONENTS IN A COMPLEX WAVE 492 |
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10.l5 |
MEASUREMENT OF TRANSMISSION COEFFICIENT .•.. |
••...... |
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493 |
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10.l6 |
AUDIOMETRY |
• |
...••.•• , •••••••••..•.. |
•.. |
•... |
•.. |
••.••••. |
494 |
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1O.l7 |
ARTICULATION |
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MEASUREMENTS |
..••.•... |
•.. |
•• |
.... |
•••• • •• |
494 |
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1O.l8 |
TESTING OF HEARING AIDS .••... |
• .•........... |
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. .••... |
•• |
495 |
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1O.l9 |
AUTOMATIC BH CURVE TRACER ........ |
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•............ |
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•. •. |
496 |
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10.20 |
ELECTRONIC MEASUREMENT OF ROUGHNESS |
•.... |
••.•••.•.• |
497 |
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10.21 |
VIBRATION MEASUREMENTS |
•.. |
•......... |
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•.•............ |
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498 |
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XI. ARCHITECTURAL ACOUSTICS AND THE COLLECTION AND DISPERSION OF SOUND
11.1 |
INTRODUCTION ••.•... |
•••.•..•.... |
•••......... |
•.... |
• . ••• |
499 |
11.2 |
DISPERSION OF SOUND |
• .. • •••••.. |
••...••.... |
••••.• |
....•• |
500 |
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A. Sound Absorption and Reverberation ..... |
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500 |
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B. Mechanism of Sound Absorption by Acoustical Mate |
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rials ............................................ |
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503 |
XVI |
CONTENTS |
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CHAPTER |
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PAGE |
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C. Functional Sound Absorbers ....................... |
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506 |
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D. Resonator Sound Absorber......................... |
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509 |
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E. Electronic Sound Absorber ......................... |
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511 |
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F. Articulation and Reverberation Time ................ |
511 |
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G. Sound Motion Picture Reproducing System .......... |
511 |
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H. Sound Re-enforcing System ........................ |
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516 |
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I. Theater Acoustics . . . . . . . . . . . . . . |
. . . . . . . . . . . . . . . . . .. |
521 |
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J. Reverberation Time of a Theater for the Reproduction |
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of Sound ......................................... |
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523 |
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K. Power Requirements for Reproducing Systems.. . . . .. |
524 |
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L. Noise at Different Locations .. . . |
. . . . . . . . . . . . . . . . . .. |
524 |
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M. Public Address Systems ........................... |
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525 |
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N. Sound Motion Picture "Drive In" Theater .......... |
529 |
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O. Orchestra and Stage Shell.................... |
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530 |
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P. General Announce and Paging Systems .............. |
531 |
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Q. Intercommunicating Systems ....................... |
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532 |
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R. Radio Receiver Operating in a Living Room. . . . . . . .. |
533 |
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S. Radio Receiver Operating in an |
Automobile ........ |
534 |
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T. Absorption of Sound in Passing Through Air. . . . . . .. |
535 |
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U. Sound Transmission Through Partitions.... . . . . . . . .. |
536 |
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11.3 |
COLLECTION OF SOUND .................................. |
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538 |
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A. Sound Collecting System ......................... |
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538 |
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B. Broadcasting Studios.............................. |
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542 |
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C. Sound Pickup Arrangement for a Radio Broadcast. . .. |
546 |
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D. Scoring and Recording Studios.. . . . . . . . . . . . . . . . . . .. |
546 |
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E. Sound Pickup Arrangements for Orchestra. . . . . . . . .. |
548 |
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F. Vocal Studios .................................... |
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551 |
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G. Reverberation Time of Broadcasting, Recording and |
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Scoring Studios............ . . . . |
. . . . . . . . . . . . . . . . . .. |
552 |
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H. Sound Stages for Motion Pictures and Television.... |
553 |
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I. Sound Pickup Arrangements for Sound Motion Pic |
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tures and Television ............................... |
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554 |
XII. SPEECH, MUSIC AND HEARING |
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12.1 |
INTRODUCTION ......................................... |
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558 |
12.2 |
HEARING MECHANISM.................................. |
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558 |
12.3 |
VOICE MECHANISM .................................... |
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560 |
12.4ARTIFICIAL VOICE MECHANISMS.. . . . . . . . . . . . . . . . . . . . . . .. 564
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A. Artificial Larynx ................................. |
564 |
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B. Voder ............................................ |
565 |
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C. Vocoder ........................................ |
" 566 |
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D. Speech Synthesizers............................... |
567 |
12.5 |
VISIBLE SPEECH ....................................... |
568 |
12.6 |
RESPONSE FREQUENCY CHARACTERISTICS OF EARS. . . . . . . . |
.. 569 |
12.7 |
LOUDNESS ............................................. |
570 |
12.8 |
PITCH ................................................ |
571 |
12.9 |
MASKING ............................................. |
572 |
12.10 NONLINEARITY OF THE EAR ............................. |
573 |
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12.11 |
EFFECT OF PHASE RELATIONS AMONG THE HARMONICS ..... |
573 |