  For integer $n\geqslant 1$ and real $u$, let $\Delta(n,u):=|\{d:d\mid
n,\,{\rm e}^u<d\leqslant {\rm e}^{u+1}\}|$. The Erd\H{o}s--Hooley
Delta-function is then defined by $\Delta(n):=\max_{u\in{\mathbb
R}}\Delta(n,u).$ We improve recent upper and lower bounds for the mean value of
this function by showing that, for large $x$, we have $$x(\log_2x)^{
3/2}\ll\sum_{n\leqslant x}\Delta(n)\ll x(\log_2x)^{ 5/2}.$$
