For example: Agilent E4440A or Anritsu 68369
Rohde and Schwarz Audio Test Instruments
Rohde and Schwarz UP300
Audio Analyzer 10 Hz to 80 kHz Analog Interfaces
Manufacturer: Rohde and Schwarz
Rohde and Schwarz UPA-3
10 Hz to 100 kHz Audio Analyzer (With Generator)
Manufacturer: Rohde and Schwarz