Presbycusis is the gradual hearing loss that occurs as a person ages. An estimated one-quarter of Americans between the ages of 65 and 75 and three-quarters of those older than 75 have some degree of hearing loss.

An audiologist is interested in the efficacy of three different types of hearing aids. He gathers three groups of hearing-impaired clients: One group receives analog hearing aids, which convert sound waves into amplified electrical signals. The second group receives digital hearing aids, which use directional microphones to control the flow of sound and convert the sound waves into numerical codes before amplifying them. The third group receives cochlear implants. The results come in, and a statistician conducts an analysis of variance.

The _ is that there is no difference between the population means (in other words, there is no treatment effect).
The is that at least one of the population means is different from another (in other words, there is an effect of at least one of the treatments).

The alternative presumption will be that the hypothesis besides making predictions is opposite to the void assumption. Its posts are generally taken as a result of a meaningful effect.

Difference:

The null hypothesis is indeed a gross generalization, which specifies there is no relation between different phenomenons under evaluation. There is no association between the two groups. An alternate solution hypothesis is a statement, that defines there is a relation between different chosen variables in this study.