This invention relates to an apparatus for producing a sound field in an acoustic space and, more particularly, to a sound field producing apparatus for converting a source signal to a direct sound mixed with a plurality of reverberation sounds.
Sound field producing apparatus have been used for reproducing a source signal to create a sound field in an acoustic space. It is the current practice to provide an impression of a widen sound field to a listener by superposing a reverberation sound on a direct sound reproduced directly from a source signal. For this purpose, such sound field producing apparatus include a reverberation signal generator circuit which provides a predetermined time delay to the source signal for converting it to a reverberation signal which is reproduced into a reverberation sound. However, the predetermined time delay provided for the reverberation signal generator circuit is normally set at a value suitable for music source reproduction and not suitable for announcement source reproduction. When reproduction is made for an announcement program, the reproduced voice appears on the direct sound and repeats on the reverberation sound in a separate manner, resulting in an unclear voice away from the natural voice. In addition, when a plurality of signals of the same frequency is reproduced to produce sounds at different times, the resulting composite sound has a level with peaks and depths at specified frequencies, resulting in an unclear voice.