Many types of silencer are already commercially available – trumpet silencers, gun silencers, social media silencers & etc – now there is a new variant, a dog silencer (proposed by a research team at Niigata University, Japan) which can help to attenuate nuisance dog barks, especially at kennels.
“This study is related to the use of natural ventilation silencers for the howling and barking (hereafter referred to as ‘barking’) of dogs.”
“[...] we present the results of silencing by throttle effect using tail-pipe.”
The silencer can achieve bark-reduction of around 4dB, or, with a new modification, up to 10dB (or, if you prefer, 1B)
Shuichi Sakamoto, Yuichi Toyoshima, Nobuaki Murayama, Toru Miyairi, Akira Hoshino, and Takatsune Narumi present Sound Attenuation Devices for Dogs Barking (Estimation of Aperture Ratio and Experimental Study of Silencer). In: International Journal of Mechanical Engineering and Applications.Vol. 2, No. 1, 2014, pp. 18-24.