The problem of hearing a particular signal may be solved by either amplifying the signal or by substituting it with another sound that can be easily heard.
(The problem of hearing a particular signal; may be solved; by either amplifying the signal or by substituting it with another sound) (another sound; can be easily heard; )
The problem of hearing a particular signal another sound
may be solved can be easily heard
by either amplifying the signal or by substituting it with another sound