ringer level for low input by monitoring the cross correlation correlation or coupling between the speaker and the microphone generally the cross correlation is a measure of similarity of two signals commonly used to find features in an unknown signal by comparing it to a known signal or standard cross correlation may be a function of for example the relative time between the signals when the cell phone is lying on a hard flat surface in a quiet room for example the correlation between the speaker and the microphone may be very good this correlation may also be used for echo cancellation during speaker phone mode when the phone is carried in a pocket or something else made out of fabric or the like i e media with good sound absorption properties like a handbag the correlation will be inferior since the microphone and or the loudspeaker is likely to be blocked and or damped table 2 illustrates the relation between the input the correlation the environment and the ringer level for a cell phone the correlation check can be carried out while a sound ring tone alarm signal or similar audible output is generated one method according to the invention as illustrated in fig3 comprises the steps of pickup of the sound 303 by the microphone background sound is picked up checking 308 the correlation between loudspeaker output and microphone input alternatively as illustrated in fig4 one embodiments includes starting 407 to generate the signal at low level and then gradually increasing 410 the level.