INDEX 



343 



Speech, power, 328 



vocoder, 319 

 Sphere, oscillating, 83 

 impedance, 83 



pulsating, 81 

 impedance, 81 

 Spherical wave, particle velocity, 12 



phase angle, 12 



pressure, 1 1 

 Stationary wave, 13 

 Strings, 36 

 Subharmonics, 3 



distortion, 137, 162 

 Supersonics, 243 

 Symbols, table, acoustical, 76 



electrical, 76 



mechanical, 76 

 Synthetic reverberation, 309 

 Systems, driving, 77 



"T" networks, 69 

 Table, absorption coefficients, 281 

 acoustic resistances, 8 

 decibels, power and voltage ratios, 



16 

 densities, 8, 48 

 dimensions of quantities, 76 

 musical scales, 335 

 noise, in various locations, 293 



reduction through various struc- 

 tures, 302 

 Poisson's ratios, 48 

 quantities; electrical, mechanical and 



acoustical, 76 

 symbols; electrical, mechanical and 



acoustical, 76 

 units, 76 



velocities of sound, 8 

 Young's moduli, 48 

 Telephone, 309 



receiver, bipolar, 226 

 crystal, 230 

 dynamic, 230 

 inductor, 232 



testing, (see testing of telephone 

 receivers) 

 Testing of, loud speakers, directional 

 characteristic, 261 



efficiency frequency characteristic, 



265 

 impedance frequency characteristic, 



268 

 nonlinear distortion characteristic, 



262 

 phase distortion characteristic, 267 

 response frequency characteristic, 

 254 

 apparatus, 255 



automobile measurements, 261 

 calibration of equipment, 258 

 living room measurements, 261 

 response, definition, 254 

 theatre measurements, 261 

 subjective measurements, 269 

 transient response characteristic, 268 

 telephone receivers, artificial, ear, 270 

 mastoid, 271 

 objective measurements, 270 

 subjective measurements, 269 

 Thermal noise in microphones, 225 

 Thermophone, 247 



Three degrees of freedom, acoustical, 61 

 electrical, 61 

 mechanical, 61 

 Throat microphone, 212 

 Timbre, 332 



Torsional vibration of bars, 46 

 Transducer, 4 



Transient response, loud speakers, 138, 

 268 

 microphones, 224, 253 

 Transmission, in tubes, 97 

 one medium to another, 98 

 through partitions, 276, 301 

 Transverse vibration, bars, 38 



strings, 37 

 Tubes, lined, 100 

 small, 78 



transmission in, 97 

 Tuning fork, 39 



Two degrees of freedom, acoustical, 61 

 electrical, 60 

 mechanical, 60 



Ultradirectional microphone, 220 

 Unidirectional microphone, 203 



