Random Noise Stimulation (Collection Of Binaural Recordings)

This compilation album features binaural recordings of synthesizer system performances using multichannel speakers between 2021 and 2024. Track 1 was performed on a computer synthesizer, created by connecting a computer to a universal serial bus (USB) device via a USB interface. The pulse-width modulation (PWM) signal output from the USB device was played through speakers. The synthesizer system consisted of a computer, USB device, line selector, buffer, filter, and mixer. Track 1 used 18-channel speakers, Tracks 2 and 3 used 32-channel speakers, Track 4 used 20-channel speakers, and Tracks 5 to 8 used 24-channel speakers. Tracks 7 and 8 were recorded on September 9, 2024. The speaker setup for these tracks featured eight front, eight rear, and eight left and right speakers arranged in a rectangle measuring 162 cm by 141 cm, with the speakers facing inward. The front and rear speakers were placed symmetrically along the long side of the rectangle, with the front speakers positioned 59.5 cm from the floor and the rear speakers 15.5 cm from the floor. The left-side speakers were placed along the left edge, starting with the first speaker 42.5 cm above the floor. The second speaker was positioned 35 cm in front of the first, at 36.5 cm above the floor. The third speaker was 70 cm in front and 29.5 cm above the floor. The fourth speaker was 105 cm in front, and 25 cm above the floor. The right-side speakers were arranged similarly from the fifth speaker to the eighth speaker. The mixer controlled sound source movement across the eight speakers, using the control signal output from the USB device. For the 24-channel setup, three mixers were employed: one for the eight front speakers, one for the eight rear speakers, and one for the eight side speakers, each using different methods for sound source movement. For recording, the dummy head microphone was positioned on a box placed at the rectangle's center of gravity. The box was 21 cm long, 36 cm wide, and 29 cm high. In Track 7, a digital delay acted as the filter, with its output played through the left and right speakers, creating unique acoustic effects. Track 8 employed four whitening filters, with the random signal output played through the 24-channel speakers. The random signal produced a more intense acoustic effect due to sound source movement. Playback for Tracks 7 and 8 was conducted experimentally. Further experimentation will explore improved filters, mixers, speakers, and dummy head microphones to ensure novel noise production in future compositions.