Synthesise onsets • onsetsync

To create an audio file of your onset data, you can call synthesise_onsets function.

Example data

Load a Cuban salsa example.

library(onsetsync)
library(tidyr)
data <- CSS_IEMP[[2]]                                                          # example

Let’s take a 10 second example. To eliminate the first 5 seconds where the instruments are not playing, let’s redefine the time to start from the first annotated cycle (Isochronous.SD.Time).

data %>%
  dplyr::filter(Isochronous.SD.Time > 5 & Isochronous.SD.Time < 15) %>%
  dplyr::mutate(Guitar = Guitar - min(Isochronous.SD.Time,na.rm=T)) %>%
  dplyr::mutate(Bass = Bass - min(Isochronous.SD.Time,na.rm=T)) -> data

Synthesise two instruments

Let’s take two instruments and create their onsets as high-pitched sound (Guitar) and short noise burst (Bass).

inst <- c('Guitar','Bass')
fs <- 22050
w <- synthesise_onsets(data = data,
                       instruments = inst, 
                       sr = fs, 
                       type =c('synth','noise'))

Plot the signal

This is downsampled for plotting in ggplot2.

scaling <- 20
ws <- signal::resample(w,fs,fs*scaling)
tmp <- data.frame(Amplitude=ws,Time=seq(0,length(ws)-1))
tmp$Time <- tmp$Time/fs*scaling
ggplot2::ggplot(tmp,ggplot2::aes(x=Time,y=Amplitude))+
  ggplot2::geom_line(color='blue')+
  ggplot2::theme_linedraw()

Save as wave file using seewave library.

seewave::savewav(wave = w, f = fs, channel = 1, filename = 'example.wav')

Further options relate to sound generators and frequency.