Note 17 - Segment Information - Segment Disclosures (Details) - USD ($)	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Revenue from Contract with Customer, Including Assessed Tax	$ 36,979,055	$ 26,306,790
Operating Income	3,136,365	(1,476,465)
Depreciation and amortization	824,889	483,087
Interest expense		20,949
Income tax expense	572,200	2,375,600
Long-lived assets	5,750,890	6,452,061
Total assets	47,119,983	41,860,797
Intersegment Eliminations [Member]
Revenue from Contract with Customer, Including Assessed Tax	907,785	313,110
LRAD Segment [Member]
Revenue from Contract with Customer, Including Assessed Tax	34,931,448	24,836,795
Operating Income	3,097,498	(1,387,902)
Depreciation and amortization	517,081	254,618
Interest expense
Income tax expense	572,200	2,375,000
Long-lived assets	2,283,344	2,478,144
Total assets	42,470,356	36,770,872
LRAD Segment [Member] | Intersegment Eliminations [Member]
Revenue from Contract with Customer, Including Assessed Tax
Genasys Segment [Member]
Revenue from Contract with Customer, Including Assessed Tax	2,047,607	1,469,995
Operating Income	38,867	(88,563)
Depreciation and amortization	307,808	228,469
Interest expense		20,949
Income tax expense
Long-lived assets	3,467,546	3,973,917
Total assets	4,649,627	5,089,925
Genasys Segment [Member] | Intersegment Eliminations [Member]
Revenue from Contract with Customer, Including Assessed Tax	$ 907,785	$ 313,110