AUSTIN (KXAN) — Austin’s Public Safety Commission discussed Tuesday the use of long-range acoustic device systems during the summer 2020 protests and potential hearing damages caused by them.

Jeff Greenwalt, assistant chief of the Austin Police Department, said an LRAD device was mounted on top of APD headquarters during the summer 2020 protests. He said these systems are beneficial when police are trying to control large crowds of people and when there is a lot of noise, making it difficult to hear police commands.

He added use of these systems during the 2020 summer protests include alerting protesters to not block public roadways or impede vehicle traffic, as well as to give people clear warnings if they’re violating the law.

APD currently has four LRAD systems available for use. These are portable and can be mounted on tripods, on top of roofs or on the top of a police vehicle. He said LRADs are not used as a “sonic weapon.”

Greenwalt said officers who sustained hearing damages during the summer 2020 protests attributed the damage to bullhorn use and fireworks shot off during the protests.

“The injuries in 2020 due to hearing did not come from the LRAD system that was mounted on top of the police headquarters,” Greenwalt said.

Kevin Welch, the president of the Electronic Frontier Foundation’s Austin chapter, challenged that assertion and said it’d be difficult to know definitively that the LRADs didn’t contribute to officers’ hearing damages.

He said information from one of the LRAD model’s use manual said that, when used at or closer than 120 feet from people, LRADs can reach decibel levels above 115 — which could cause possible hearing damages, Welch said.

“By the use manual’s own stuff, I have to debate the conclusion that the hearing damage was definitely not caused by the LRADs,” Welch said.

Information provided by APD to commissioners Tuesday outlined various activities and corresponding decibel levels, including the department’s use of LRADs during the protests.

  • Conversational speech: 60 decibels
  • School cafeteria: 85 decibels
  • LRAD from ~50 feet away: 109 decibels (used during summer 2020 protests)
  • Handheld bullhorn, megaphone from ~6 feet away: 100-120 decibels
  • LRAD from ~13 feet away: 121 decibels
  • Fireworks: 140-165 decibels

Welch said he was unfamiliar with the manual being cited and requested access to the documents. Welch said he will share the documents with APD and commissioners as well to look into the system’s uses and any potential concerns related to them.