We observe that this item fulfils a crucial need shared by all languages – the efficient signalling of problems of hearing and understanding – and we propose that its form is constrained by selective pressures in a conversational environment that is essentially the same in all languages.
1	We	we	PRON	PRP	Case=Nom|Number=Plur|Person=1|PronType=Prs	2	nsubj	2:nsubj	Discourse=attribution-positive:63->64:2|Entity=(43-person-giv:act-cf1*-1-ana)
2	observe	observe	VERB	VBP	Mood=Ind|Number=Plur|Person=1|Tense=Pres|VerbForm=Fin	0	root	0:root	_
3	that	that	SCONJ	IN	_	6	mark	6:mark	Discourse=joint-sequence_m:64->31:3
4	this	this	DET	DT	Number=Sing|PronType=Dem	5	det	5:det	Entity=(49-abstract-giv:inact-cf6-2-coref
5	item	item	NOUN	NN	Number=Sing	6	nsubj	6:nsubj	Entity=49)
6	fulfils	fulfil	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	2	ccomp	2:ccomp	_
7	a	a	DET	DT	Definite=Ind|PronType=Art	9	det	9:det	Entity=(88-abstract-new-cf5-3-coref
8	crucial	crucial	ADJ	JJ	Degree=Pos	9	amod	9:amod	_
9	need	need	NOUN	NN	Number=Sing	6	obj	6:obj	_
10	shared	share	VERB	VBN	Tense=Past|VerbForm=Part	9	acl	9:acl	Discourse=elaboration-attribute:65->64:0
11	by	by	ADP	IN	_	13	case	13:case	_
12	all	all	DET	DT	PronType=Tot	13	det	13:det	Entity=(27-abstract-giv:act-cf4-2-coref
13	languages	language	NOUN	NNS	Number=Plur	10	obl:agent	10:obl:agent	Entity=27)88)
14	–	-	PUNCT	:	_	17	punct	17:punct	Discourse=elaboration-additional:66->64:1
15	the	the	DET	DT	Definite=Def|PronType=Art	17	det	17:det	Entity=(88-abstract-giv:act-cf5-3-appos
16	efficient	efficient	ADJ	JJ	Degree=Pos	17	amod	17:amod	_
17	signalling	signalling	NOUN	NN	Number=Sing	9	appos	9:appos	_
18	of	of	ADP	IN	_	19	case	19:case	_
19	problems	problem	NOUN	NNS	Number=Plur	17	nmod	17:nmod:of	Entity=(89-abstract-new-cf7-1-sgl
20	of	of	ADP	IN	_	21	case	21:case	Discourse=elaboration-additional:67->66:0
21	hearing	hearing	NOUN	NN	Number=Sing	19	nmod	19:nmod:of	Entity=(90-abstract-new-cf8-1-sgl)
22	and	and	CCONJ	CC	_	23	cc	23:cc	Discourse=joint-list_m:68->67:0
23	understanding	understanding	NOUN	NN	Number=Sing	21	conj	19:nmod:of|21:conj:and	Entity=(91-abstract-new-cf9-1-sgl)89)88)
24	–	-	PUNCT	:	_	27	punct	27:punct	_
25	and	and	CCONJ	CC	_	27	cc	27:cc	Discourse=attribution-positive:69->70:2
26	we	we	PRON	PRP	Case=Nom|Number=Plur|Person=1|PronType=Prs	27	nsubj	27:nsubj	Entity=(43-person-giv:act-cf1*-1-ana)
27	propose	propose	VERB	VBP	Mood=Ind|Number=Plur|Person=1|Tense=Pres|VerbForm=Fin	2	conj	2:conj:and	_
28	that	that	SCONJ	IN	_	32	mark	32:mark	Discourse=joint-list_m:70->64:3
29	its	its	PRON	PRP$	Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs	30	nmod:poss	30:nmod:poss	Entity=(83-abstract-giv:act-cf3-2-coref(87-abstract-giv:act-cf2-1-ana)
30	form	form	NOUN	NN	Number=Sing	32	nsubj:pass	32:nsubj:pass	Entity=83)
31	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	32	aux:pass	32:aux:pass	_
32	constrained	constrain	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	27	ccomp	27:ccomp	_
33	by	by	ADP	IN	_	35	case	35:case	_
34	selective	selective	ADJ	JJ	Degree=Pos	35	amod	35:amod	Entity=(92-abstract-new-cf10-2-sgl
35	pressures	pressure	NOUN	NNS	Number=Plur	32	obl:agent	32:obl:agent	Entity=92)
36	in	in	ADP	IN	_	39	case	39:case	_
37	a	a	DET	DT	Definite=Ind|PronType=Art	39	det	39:det	Entity=(93-abstract-new-cf11-3-coref
38	conversational	conversational	ADJ	JJ	Degree=Pos	39	amod	39:amod	_
39	environment	environment	NOUN	NN	Number=Sing	35	nmod	35:nmod:in|44:nsubj	_
40	that	that	PRON	WDT	PronType=Rel	44	nsubj	39:ref	Discourse=elaboration-attribute:71->70:0
41	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	44	cop	44:cop	_
42	essentially	essentially	ADV	RB	Degree=Pos	44	advmod	44:advmod	_
43	the	the	DET	DT	Definite=Def|PronType=Art	44	det	44:det	_
44	same	same	ADJ	JJ	Degree=Pos	39	acl:relcl	39:acl:relcl	_
45	in	in	ADP	IN	_	47	case	47:case	_
46	all	all	DET	DT	PronType=Tot	47	det	47:det	Entity=(27-abstract-giv:act-cf4-2-coref
47	languages	language	NOUN	NNS	Number=Plur	44	obl	44:obl:in	Entity=27)93)|SpaceAfter=No
48	.	.	PUNCT	.	_	2	punct	2:punct	_
