soundgen (version 2.7.2)

getHNR: Get HNR

Description

Calculates the harmonics-to-noise ratio (HNR) - that is, the ratio between the intensity (root mean square amplitude) of the harmonic component and the intensity of the noise component. Normally called by analyze.

Usage

getHNR(
  x = NULL,
  samplingRate = NA,
  acf_x = NULL,
  lag.min = 2,
  lag.max = length(x),
  interpol = c("none", "parab", "spline", "sinc")[4],
  wn = "hanning",
  idx_max = NULL
)

Value

A list of three components: f0 = frequency corresponding to the peak of the autocorrelation function; max_acf = amplitude of the peak of the autocorrelation function on a scale of (0, 1); HNR = 10 * log10(x / (1 - max_acf)).

Arguments

x

time series (a numeric vector)

samplingRate

sampling rate

acf_x

pre-computed autocorrelation function of input x, if already available

lag.min, lag.max

minimum and maximum lag to consider when looking for peaks in the ACF; lag.min = samplingRate/pitchCeiling, lag.max = samplingRate/pitchFloor

interpol

method of improving the frequency resolution by interpolating the ACF: "none" = don't interpolate; "parab" = parabolic interpolation on three points (local peak and its neighbors); "spline" = spline interpolation; "sinc" = sin(x)/x interpolation to a continuous function followed by a search for local peaks using Brent's method

wn

window applied to x (unless acf_x is provided instead of x) as well as to the sinc interpolation

idx_max

(internal) the index of the peak to investigate, if already estimated

References

Boersma, P. (1993). Accurate short-term analysis of the fundamental frequency and the harmonics-to-noise ratio of a sampled sound. In Proceedings of the institute of phonetic sciences (Vol. 17, No. 1193, pp. 97-110).

Examples

signal = sin(2 * pi * 150 * (1:16000)/16000)
signal = signal / sqrt(mean(signal^2))
noise = rnorm(16000)
noise = noise / sqrt(mean(noise^2))
SNR = 40
s = signal + noise * 10^(-SNR/20)
soundgen:::getHNR(s, 16000, lag.min = 16000/1000,
lag.max = 16000/75, interpol = 'none')
soundgen:::getHNR(s, 16000, lag.min = 16000/1000,
lag.max = 16000/75, interpol = 'parab')
soundgen:::getHNR(s, 16000, lag.min = 16000/1000,
lag.max = 16000/75, interpol = 'spline')
soundgen:::getHNR(s, 16000, lag.min = 16000/1000,
lag.max = 16000/75, interpol = 'sinc')