Revenue By Market (Schedule Of Net Revenue By Market)(Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue, Major Customer [Line Items]
Total Revenue	$ 30,160	$ 22,524	$ 55,523	$ 43,739
Products and Services Transferred at Point in Time [Member]
Revenue, Major Customer [Line Items]
Total Revenue	9,962	8,952	19,392	17,987
Products and Services Transferred over Time [Member]
Revenue, Major Customer [Line Items]
Total Revenue	20,198	13,572	36,131	25,752
Body Worn Devices Segment [Member]
Revenue, Major Customer [Line Items]
Total Revenue	28,108	21,115	51,680	40,914
Hearing Health Direct-to-End Consumer [Member]
Revenue, Major Customer [Line Items]
Total Revenue	2,052	1,409	3,843	2,825
Medical [Member] | Body Worn Devices Segment [Member]
Revenue, Major Customer [Line Items]
Total Revenue	20,198	13,572	36,131	25,752
Medical [Member] | Body Worn Devices Segment [Member] | Products and Services Transferred over Time [Member]
Revenue, Major Customer [Line Items]
Total Revenue	20,198	13,572	36,131	25,752
Hearing Health Market [Member] | Body Worn Devices Segment [Member]
Revenue, Major Customer [Line Items]
Total Revenue	6,390	6,035	12,200	12,272
Hearing Health Market [Member] | Body Worn Devices Segment [Member] | Products and Services Transferred at Point in Time [Member]
Revenue, Major Customer [Line Items]
Total Revenue	6,390	6,035	12,200	12,272
Professional Audio Communications [Member] | Body Worn Devices Segment [Member]
Revenue, Major Customer [Line Items]
Total Revenue	1,520	1,508	3,349	2,890
Professional Audio Communications [Member] | Body Worn Devices Segment [Member] | Products and Services Transferred at Point in Time [Member]
Revenue, Major Customer [Line Items]
Total Revenue	1,520	1,508	3,349	2,890
Hearing Health Direct-to-End Consumer (DTEC) Market [Member] | Hearing Health Direct-to-End Consumer [Member]
Revenue, Major Customer [Line Items]
Total Revenue	2,052	1,409	3,843	2,825
Hearing Health Direct-to-End Consumer (DTEC) Market [Member] | Hearing Health Direct-to-End Consumer [Member] | Products and Services Transferred at Point in Time [Member]
Revenue, Major Customer [Line Items]
Total Revenue	$ 2,052	$ 1,409	$ 3,843	$ 2,825