Segment Reporting (Summary Of Data By Industry Segment) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Revenue, net	$ 21,503	$ 29,570	$ 29,570
Income (loss) from continuing operations before income taxes and discontinued operations	(1,961)	1,099
Depreciation and amortization	921	797
Capital expenditures	1,678	938
Goodwill	9,551		9,551
Body Worn Devices [Member]
Segment Reporting Information [Line Items]
Revenue, net	20,330	27,940
Income (loss) from continuing operations before income taxes and discontinued operations	(1,078)	2,581
Depreciation and amortization	895	736
Capital expenditures	1,678	918
Identifiable assets (excluding goodwill)	99,802		101,311
Goodwill	9,551		9,551
Hearing Health DTEC [Member]
Segment Reporting Information [Line Items]
Revenue, net	1,173	1,630
Income (loss) from continuing operations before income taxes and discontinued operations	(883)	(1,482)
Depreciation and amortization	26	61
Capital expenditures		$ 20
Identifiable assets (excluding goodwill)	$ 2,365		$ 2,651

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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