Revenue Information - Revenue into Primary Product Groups and Major Regions (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue [Line Items]
Revenue	$ 5,483	$ 7,375	$ 9,661	$ 14,920
North and South America [Member]
Revenue [Line Items]
Revenue	3,384	3,184	4,954	6,960
Asia Pacific (includes Middle East, India and Australia)
Revenue [Line Items]
Revenue	1,672	2,468	3,368	4,542
Europe and Africa [Member]
Revenue [Line Items]
Revenue	427	1,723	1,339	3,418
Audio conferencing [Member]
Revenue [Line Items]
Revenue	2,289	3,277	4,618	6,453
Microphones [Member]
Revenue [Line Items]
Revenue	2,688	3,123	3,883	6,051
Video products [Member]
Revenue [Line Items]
Revenue	$ 506	$ 975	$ 1,160	$ 2,416