音声データ (MP3) をRでプロットする

plot_sound.R

library(tuneR)
library(ggplot2)

voice_orig <- readMP3(file.path("voice.mp3"))

# 音声の切り出し
start <- 0.6 * voice_orig@samp.rate
end <- 1.1 * voice_orig@samp.rate
voice <- voice_orig[start:end]

# データフレームへの変換
sample <- seq(1:length(voice@left))
time <- sample/voice@samp.rate
sample.left <- as.vector(cbind(voice@left))
voice_df <- data.frame(sample, time, sample.left)

# ノイズの付与
voice_df[["noise_sample.left"]] <- sample.left + runif(n = length(sample.left), min = min(sample.left) / 2, max = max(sample.left) / 2)


# プロット
ggplot(voice_df, aes(x = time, y = sample.left)) + geom_line() + theme_void()
ggsave("voice_clear.png", width = 10, height = 4, units = "cm")

ggplot(voice_df, aes(x = time, y = noise_sample.left)) + geom_line() + theme_void()
ggsave("voice_noise.png", width = 10, height = 4, units = "cm")