good wheel builders (e.g. SON in Germany) use tensiometers. My mech in Switzerland checked every spoke, when one spoke was broken...
I use both: my hearing and the tensiometer for the final check. The tension depends on the brand/type/construction of the rim the type of spokes as well.
Edit: the cheap ztto tensiometers are not very solid, however the ones from ZTTO, which look like the DT Swiss Tensiometers, are supposed to be better. The DT Swiss are the best (Parktool: between). I've got a cheap Amazon (China)tensiometer, the values are reproducable, so I'm happy with it. Would recomment a bit of grease onto the joints of the tensiometer.