How can I get a dataframe of frequency and time from a wav file in R?

Question

I'd like to try to distinguish two speakers in a wav file. The most straightforward way seems like it should be to extract frequency info from the file, and use time to match frequency with a given part of the file. I don't see a function in tuneR or seewave to easily extract a dataframe like this. What's the easiest way to do it? Thanks!

Answer 1

Here's something that might help. The spectro function returns time, frequency and amplitude and with some manipulation using functions in reshape2 and dplyr you can get a data frame.

library(seewave)
library(tuneR)
library(reshape2)
library(dplyr)

data("pellucens")
writeWave(pellucens, "pellucens.wav")
wav = readWave("pellucens.wav")

ss = spectro(wav, plot = F)
mm =
  melt(ss$amp, value.name = "Amplitude") %>%
  dplyr::select(FrequencyIndex = Var1, TimeIndex = Var2, Amplitude)
ff =
  melt(ss$freq, value.name = "Frequency") %>%
  dplyr::mutate(FrequencyIndex = row_number(), Frequency = Frequency * 1000)
tt =
  melt(ss$time, value.name = "Time") %>%
  dplyr::mutate(TimeIndex = row_number())
sp =
  mm %>%
  dplyr::left_join(ff, by = "FrequencyIndex") %>%
  dplyr::left_join(tt, by = "TimeIndex") %>%
  dplyr::select(Time, Frequency, Amplitude)

# head(sp)
#  Time Frequency Amplitude
#1    0   0.00000 -57.72730
#2    0  21.53320 -63.55554
#3    0  43.06641 -85.05077
#4    0  64.59961 -91.29989
#5    0  86.13281 -83.86144
#6    0 107.66602 -81.54240