56 research outputs found
Annoyance due to modulation noise and drop-outs in magnetic sound recording
In addition to a constant background noise, sound recordings on magnetic tape may also suffer from modulation noise and 'drop-outs'. The level of the modulation noise is proportional to that of the signa!. Modulation noise is more readily audiblein recordings of solo instruments than in orchestral music; listening tests have shown that for the flute the audibility threshold lies at a signal-to-noise ratio as high as 40 dB. The frequency with which drop-outs occur is a matter of tape quality. Listening tests have been carried out to determine the annoyance caused by drop-outs as a function oftheir duration, the degree of attenuation and the frequency of occurrence. The results of these experiments have been applied in the DAMA annoyance meter, which can measure these quantities for an audio tape and assign a quality rating to it
Frequency discrimination in short sinusoids as a function of signal-to-noise ratio
No abstract
Luisteren naar impulsreeksen met ongelijke intervallen
The borderland between perfectly periodic and aperiodic sounds is explored, using trains of sharp pulses as a test signal. Jitter £ .e. the r. m. s. deviation from the average interval proves to be a meaningful measure of the imperfection of periodicity. It is argued, that many sources of (musical) sound are imperfectly periodic.Measurements of jitter in a bowed string are presented.Limits for the perception of pitch and imperfect periodicity are discussed in terms of relative jitter,without going into the details of actual psychoacoustical experiments. Finally,an experiment is described showing that the hearing system is able to perceive jitter, without having acces to the components of the sound spectrum
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