  We obtain resonances for short exponential sums involving Fourier
coefficients of Maass forms for $\mathrm{SL}(n,\mathbb Z)$. This involves
deriving asymptotics for the integrals appearing in the $\mathrm{GL}(n)$
Voronoi summation formula. As an application, we also prove an $\Omega$-result
for short sums of Fourier coefficients.
