mixAtSNR: Mix signals at specific SNR

In soundgen: Sound Synthesis and Acoustic Analysis

Mix signals at specific SNR

Description

Adds two partly overlapping vectors, such as two waveforms or "signal" and "noise", at specific RMS or loudness levels. The location at which vector 2 ("noise") is pasted is defined by insertionPoint. Algorithm: both vectors are padded with zeros to match in length, rescaled, added, and re-normalized. All NA's are converted to 0. addVectors is the former name from soundgen 2.x, preserved for back-compatibility.

Usage

mixAtSNR(
  signal,
  noise,
  insertionPoint = 1L,
  normalize = TRUE,
  SNR = NULL,
  type = c("rms", "RMS", "peak", "loudness"),
  loudness_pars = list()
)

addVectors(
  signal,
  noise,
  insertionPoint = 1L,
  normalize = TRUE,
  SNR = NULL,
  type = c("rms", "RMS", "peak", "loudness"),
  loudness_pars = list()
)

Arguments

signal, noise	numeric vectors
insertionPoint	the index of element in vector 1 at which vector 2 will be inserted (any integer, can also be negative)
normalize	if TRUE, the output is normalized to range from -1 to +1
SNR	signal-to-noise ratio, dB
type	rescale noise to target SNR relative to signal based on root mean square amplitude ('rms' or 'RMS', default), peak amplitude ('peak'), or mean subjective loudness in sone ('loudness')
loudness_pars	a list of parameters passed to getLoudness if type = 'loudness'

Value

A numeric vector.

Examples

v1 = 1:6
v2 = rep(100, 3)
addVectors(v1, v2, insertionPoint = 5, normalize = FALSE)
addVectors(v1, v2, insertionPoint = -4, normalize = FALSE)
addVectors(v1, rep(100, 15), insertionPoint = -4, normalize = FALSE)
# note the asymmetry: insertionPoint refers to the first arg
addVectors(v1, v2, insertionPoint = -4, normalize = FALSE)

v3 = rep(100, 15)
addVectors(v1, v3, insertionPoint = -4, normalize = FALSE)
addVectors(v2, v3, insertionPoint = 7, normalize = FALSE)
addVectors(1:6, 3:6, insertionPoint = 3, normalize = FALSE)

# add noise to a sound at a particular SNR
signal = rep(c(rep(0, 500), cospi(2 * 440 * (1:1000) / 16000)), 2)
noise = rnorm(length(signal))
osc(mixAtSNR(signal, noise, SNR = 6), samplingRate = 16000)
osc(mixAtSNR(signal, noise, SNR = 6, type = 'peak'), samplingRate = 16000)
osc(mixAtSNR(signal, noise, SNR = 6, type = 'loudness',
  loudness_pars = list(samplingRate = 16000, SPL = 80)), samplingRate = 16000)
osc(mixAtSNR(signal, noise, SNR = 12), samplingRate = 16000)
osc(mixAtSNR(signal, noise, SNR = 0), samplingRate = 16000)

# no rescaling (SNR = NULL)
osc(mixAtSNR(signal, noise, SNR = NULL), samplingRate = 16000)
osc(mixAtSNR(signal, noise/4, SNR = NULL), samplingRate = 16000)

soundgen documentation built on Sept. 20, 2026, 5:07 p.m.