Vacuum pressure of a gas in a compartment (1) is measured. The vacuum pressure is established by a pump arrangement (3,5) with a pulsating pumping effect (g(t)). The shape of the resulting pulsation of the pressure (p(t)) in compartment (1) is exploited (15) as an indication of the operation status of the pump arrangement (3,5).

Vacuum pressure of a gas in a compartment (1) is measured. The vacuum pressure is established by a pump arrangement (3,5) with a pulsating pumping effect (g(t)). The shape of the resulting pulsation of the pressure (p(t)) in compartment (1) is exploited (15) as an indication of the operation status of the pump arrangement (3,5).

In accordance with an implementation of the disclosure, systems and methods are provided for providing an estimate for noise in a speech signal. An instantaneous power value is received that corresponds to a frequency index of a portion of the speech signal. A first weighted power value is updated based on the instantaneous power value and a first weighting parameter. A second weighted power value is updated based on the first weighed power value and a second weighting parameter. An estimate of the noise is computed from the instantaneous power value and the second weighted power value.