Segment Reporting (Summary Of Data By Industry Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Revenue, net	$ 27,367	$ 26,893	$ 72,472	$ 85,800
Impairment loss				(3,765)
(Loss) income from continuing operations before income taxes and discontinued operations	701	(203)	(3,505)	(2,497)
Depreciation and amortization	1,258	820	3,311	2,448
Capital expenditures	610	1,428	2,562	3,787
Body Worn Devices [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, net	26,415	25,383	68,960	80,924
(Loss) income from continuing operations before income taxes and discontinued operations	561	750	(1,868)	5,106
Depreciation and amortization	1,244	712	3,245	2,210
Capital expenditures	578	1,374	2,530	3,651
Hearing Health DTEC [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, net	952	1,510	3,512	4,876
Impairment loss				(3,765)
(Loss) income from continuing operations before income taxes and discontinued operations	140	(953)	(1,637)	(7,603)
Depreciation and amortization	14	108	66	238
Capital expenditures	$ 32	$ 54	$ 32	$ 136