Annoyance of distortions of speech: experiments on the influence of interruptions and random-noise impulses

The present study is concerned with the annoyance produced by either suppressing or temporally masking short segments of a speech signal ('signal-plus-gap condition' and 'signal-plus-noise condition'). Test samples differing in gap duration, noise-impulse duration, and intermittent signal duration, were presented to subjects with three different kinds of sound presentation, i.e., monotic, diotic, and binaural, the latter including reverberation. It was found that basically there is a pronounced tendency of signal interruptions to be more annoying than superimposed noise impulses of the same length. This effect is essentially the same both for monotic and diotic presentation. According to the results of the binaural experiment, sound reflections in a room have little or no influence on the annoyance of interruptions and enhance the annoyance of noise impulses. The results suggest that the annoyance of speech distortions of the type described is essentially dependent on loss of information (i.e. inaudibility of speech segments) rather than primary sensory attributes such as roughness.