Segment Reporting (Summary Of Data By Industry Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Revenue, net	$ 23,602	$ 29,336	$ 45,105	$ 58,906
(Loss) income from continuing operations before income taxes and discontinued operations	(2,245)	(3,393)	(4,206)	(2,294)
Depreciation and amortization	1,132	818	2,053	1,628
Capital expenditures	274	1,405	1,952	2,359
Body Worn Devices [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, net	22,215	27,600	42,545	55,540
(Loss) income from continuing operations before income taxes and discontinued operations	(1,351)	1,775	(2,429)	4,356
Depreciation and amortization	1,106	772	2,001	1,498
Capital expenditures	274	1,343	1,952	2,277
Hearing Health DTEC [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, net	1,387	1,736	2,560	3,366
(Loss) income from continuing operations before income taxes and discontinued operations	(894)	(5,168)	(1,777)	(6,650)
Depreciation and amortization	$ 26	46	$ 52	130
Capital expenditures		$ 62		$ 82