nzilbb.annotator.labelmapper

Label Mapper

This annotator creates a mapping between the labels of pairs of layers, by finding the minimum edit path between them.

For example, this layer manager can be used to tag each phone in a word with its likely counterpart in another phonemic transcription:

d	ɪ	f	ə	ɹ	n̩	t
↓	↓	↓		↓	↓	↓
d	ɪ	f		ɹ	ən	t

… or phonemic encoding:

d	ɪ	f	ə	ɹ	n̩	t
↓	↓	↓	↓	↓	↓	↓
D	IH1	F	ER0	R	AH0 N	T

One possible use is to map non-rhotic phones to their equivalent rhotic transcription:

f	αɪ	ə	f	αɪ	t	ə
↓	↓	↓	↓	↓	↓	↓
f	αɪ	əɹ	f	αɪ	t	əɹ

Forced Alignment Comparison

The Label Mapper can also be used to compare alternative word/phone alignments - e.g. you may have manual word/phone alignment that you want to compare with word/phone alignmentd automatically generated by HTK, in order to measure the accuracy of the automatic alignments.

In this case, you specify two mappings, a main mapping between a pair of word alignment layers, and a sub-mapping between a paird of phone alignment layers.

Word Source	CMUDictWord	DIFFERENT								FIREFIGHTER
		↓								↓
Word Target	orthography	different								firefighter
Phone Source	P2FAPhone	D	IH1	F	ER0	R	AH0	N	T	F	AY1	R	F	AY2	T	ER0
		↓	↓	↓		↓	↓	↓	↓	↓	↓	↓	↓	↓	↓	↓
Phone Target	segments	d	I	f		r	@	n	t	f	2	@	f	2	t	@

These mappings are tracked in detail, to facilitate comparison of alignment and labelling. Mapping information can be accessed via the 'extensions' page of this annotator.