Perceptual Evaluation of Speech Quality (PESQ)

Module Interface

class torchmetrics.audio.pesq.PerceptualEvaluationSpeechQuality(fs, mode, n_processes=1, **kwargs)

Calculate Perceptual Evaluation of Speech Quality (PESQ).

It’s a recognized industry standard for audio quality that takes into considerations characteristics such as: audio sharpness, call volume, background noise, clipping, audio interference etc. PESQ returns a score between -0.5 and 4.5 with the higher scores indicating a better quality.

This metric is a wrapper for the pesq package. Note that input will be moved to cpu to perform the metric calculation.

As input to forward and update the metric accepts the following input

• preds (Tensor): float tensor with shape (...,time)

• target (Tensor): float tensor with shape (...,time)

As output of forward and compute the metric returns the following output

• pesq (Tensor): float tensor of PESQ value reduced across the batch

Hint

Using this metrics requires you to have pesq install. Either install as pip install torchmetrics[audio] or pip install pesq. pesq will compile with your currently installed version of numpy, meaning that if you upgrade numpy at some point in the future you will most likely have to reinstall pesq.

Caution

The forward and compute methods in this class return a single (reduced) PESQ value for a batch. To obtain a PESQ value for each sample, you may use the functional counterpart in perceptual_evaluation_speech_quality().

Parameters:

• fs (int) – sampling frequency, should be 16000 or 8000 (Hz)

• mode (str) – 'wb' (wide-band) or 'nb' (narrow-band)

• keep_same_device – whether to move the pesq value to the device of preds

• n_processes (int) – integer specifying the number of processes to run in parallel for the metric calculation. Only applies to batches of data and if multiprocessing package is installed.

• kwargs (Any) – Additional keyword arguments, see Advanced metric settings for more info.

Raises:

• ModuleNotFoundError – If pesq package is not installed

• ValueError – If fs is not either 8000 or 16000

• ValueError – If mode is not either "wb" or "nb"

Example

>>> from torch import randn
>>> from torchmetrics.audio import PerceptualEvaluationSpeechQuality
>>> preds = randn(8000)
>>> target = randn(8000)
>>> pesq = PerceptualEvaluationSpeechQuality(8000, 'nb')
>>> pesq(preds, target)
tensor(2.2885)
>>> wb_pesq = PerceptualEvaluationSpeechQuality(16000, 'wb')
>>> wb_pesq(preds, target)
tensor(1.6805)

plot(val=None, ax=None)

Plot a single or multiple values from the metric.

Parameters:

• val (Union[Tensor, Sequence[Tensor], None]) – Either a single result from calling metric.forward or metric.compute or a list of these results. If no value is provided, will automatically call metric.compute and plot that result.

• ax (Optional[Axes]) – An matplotlib axis object. If provided will add plot to that axis

Return type:

tuple[Figure, Union[Axes, ndarray]]

Returns:

Figure and Axes object

Raises:

ModuleNotFoundError – If matplotlib is not installed

>>> # Example plotting a single value
>>> import torch
>>> from torchmetrics.audio import PerceptualEvaluationSpeechQuality
>>> metric = PerceptualEvaluationSpeechQuality(8000, 'nb')
>>> metric.update(torch.rand(8000), torch.rand(8000))
>>> fig_, ax_ = metric.plot()

>>> # Example plotting multiple values
>>> import torch
>>> from torchmetrics.audio import PerceptualEvaluationSpeechQuality
>>> metric = PerceptualEvaluationSpeechQuality(8000, 'nb')
>>> values = [ ]
>>> for _ in range(10):
...     values.append(metric(torch.rand(8000), torch.rand(8000)))
>>> fig_, ax_ = metric.plot(values)

Functional Interface

torchmetrics.functional.audio.pesq.perceptual_evaluation_speech_quality(preds, target, fs, mode, keep_same_device=False, n_processes=1)

Calculate Perceptual Evaluation of Speech Quality (PESQ).

It’s a recognized industry standard for audio quality that takes into considerations characteristics such as: audio sharpness, call volume, background noise, clipping, audio interference etc. PESQ returns a score between -0.5 and 4.5 with the higher scores indicating a better quality.

This metric is a wrapper for the pesq package. Note that input will be moved to cpu to perform the metric calculation.

Hint

Usingsing this metrics requires you to have pesq install. Either install as pip install torchmetrics[audio] or pip install pesq. Note that pesq will compile with your currently installed version of numpy, meaning that if you upgrade numpy at some point in the future you will most likely have to reinstall pesq.

Parameters:

• preds (Tensor) – float tensor with shape (...,time)

• target (Tensor) – float tensor with shape (...,time)

• fs (int) – sampling frequency, should be 16000 or 8000 (Hz)

• mode (str) – 'wb' (wide-band) or 'nb' (narrow-band)

• keep_same_device (bool) – whether to move the pesq value to the device of preds

• n_processes (int) – integer specifying the number of processes to run in parallel for the metric calculation. Only applies to batches of data and if multiprocessing package is installed.

Return type:

Tensor

Returns:

Float tensor with shape (...,) of PESQ values per sample

Raises:

• ModuleNotFoundError – If pesq package is not installed

• ValueError – If fs is not either 8000 or 16000

• ValueError – If mode is not either "wb" or "nb"

• RuntimeError – If preds and target do not have the same shape

Example

>>> from torch import randn
>>> from torchmetrics.functional.audio.pesq import perceptual_evaluation_speech_quality
>>> preds = randn(8000)
>>> target = randn(8000)
>>> perceptual_evaluation_speech_quality(preds, target, 8000, 'nb')
tensor(2.2885)
>>> perceptual_evaluation_speech_quality(preds, target, 16000, 'wb')
tensor(1.6805)