Fairly proficient esophageal speakers produce a significant level of hissing through the tracheostoma if they try to speak too fast.
To solve this problem, apply abdominal pressure during vocalization while keeping exhalation from a tracheostoma to a minimum insofar as possible. These noises can be fairly minimized by speaking only by pushing up the diaphragm, pronouncing slowly, and concentrating on this effort.
(2) Speaking under tension
Those who produce heavy "hissing" sounds through the tracheostoma cannot apply the strong abdominal pressure, as described above. For this reason, they try to speak by contracting the chest. The result is a stiff neck and aching shoulders. Since the original amount of air in the esophagus is small, the resulting voice gives the impression of agony or choking.
Some new students produce a slight soft "po!" when making the basic sound "a." Those able to do this will usually learn fast in subsequent practice.
In contrast, those who tend to produce a "stiff" or strangled sound tend to need more time in practice.