76 Seconds of Pulses for Two Loudspeakers

2005 (for two-channel fixed media), 1'16"

Fergal Dowling · 76 Seconds Of Pulses

76 Seconds of Pulses for Two Loudspeakers is a short play on psychoacoustic effects and human aural perception. It is a noise-based electroacoustic work in which rhythmic noise pulses reveal an underlying three-part contrapuntal rhythmic structure.

To develop the rhythmic material, a simple harmonic outline is transposed downwards to corresponding sub-audio frequencies. These low-frequency rates are rendered as pulses of noise-based samples and the result is projected as spatially segregated sound streams, which describe a simple rhythmic relationship.

Three musical parts emerge as rhythmic streams of pulses operating at differing rates across two channels. If the two channels are summed our ability to distinguish between the parts collapses and we perceive only a single stream with an irregular rhythm. In mono reproduction each new entry of a spatially segregated part can be heard for a short time before the rhythmic streams combine and become indistinguishable.

While the piece depends on the use of two channels to establish and maintain two separate rhythmic streams, the channels must be auditioned over loudspeakers – not over headphones. The loudspeakers may be positioned in a variety of arrangements: in the normal stereo pair, as two separated speakers positioned on a stage, at the extreme sides of the audience, or even to the rear of the audience. There is no intended listener orientation.