  Exploring superconductors which can possess pairing mechanism other than the
BCS predicted s-wave have continually attracted considerable interest.
Superconductors with low-lying phonons may exhibit unconventional
superconductivity as the coupling of electrons with these low-lying phonons can
potentially affect the nature of the superconducting ground state, resulting in
strongly coupled superconductivity. In this work, by using magnetization, AC
transport, specific heat, and muon spin rotation/relaxation ($\mu$SR)
measurements, we report a detailed investigation on the superconducting ground
state of the strongly coupled superconductor, IrGe, that has a transition
temperature, T$_{C}$, at 4.7 K. Specific heat (SH), and transverse field
$\mu$SR is best described with an isotropic s-wave model with strong
electron-phonon coupling, indicated by the values of both
$\Delta(0)/k_{B}T_{C}$ = 2.3, 2.1 (SH, $\mu$SR), and $\Delta
C_{el}/\gamma_{n}T_{C}$ = 2.7. Zero-field $\mu$SR measurements confirm the
presence of time-reversal symmetry in the superconducting state of IrGe.
