Tool for labeling audio
Audacity is a free and open source audio editing software, available for all common desktop operating systems. It can be used to annotate audio, by using Label Tracks. You can have a label at a certain position, or covering a selection of time.

Annotating


Open or import your audio into Audacity
Select the audio track you want to annotate.
Click Track -&gt; Edit Labels to add a new Label track
Select where in the track you want to annotate
Insert new label using keyboard shortcut Ctrl + B


Repeat until done with the track.



Export annotations

Export the labels using File -&gt; Export -&gt; Export Labels

Loading annotations

To load the labels into Python, you can use this snippet of code:

import pandas

path = 'PATH/TO/FILE'
labels = pandas.read_csv(path, sep='\t', header=None,
                        names=['start', 'end', 'annotation'],
                        dtype=dict(start=float,end=float,annotation=str))