I am old enough to have 'come up' in shops using a combination of lineshafting and electric motor 'conversion' drives on flat belt driven machine tools. The slap of belting and the click of the lacing hooks is a natural sound, something that 'comes with the territory' of owning and using old flat belt driven machine tools. Personally, I like the sounds of flat belting slapping and lacing hooks clicking. But, that's my own preference. Old machine tools, by their very nature, are going to have a variety of sounds- open gearing on a 'camelback' drill, even with open gear lube on the teeth, will add its own sound. Throw in the back gears and get additional sounds, particularly when open spur gearing is run unloaded. There is often a little random additional sound from the gear lash when spur gearing is run unloaded.
I run belt lacing hooks on my flat belt driven machine tools. Easy enough to put in, and easy enough to 'take a piece out' if a belt stretches and 'takes a set', becoming too slack for transmitting much, if any, power. As a kid attending Brooklyn Technical HS in the 60's, we still had quite a bit of lineshaft driven machine tools. We were taught to care for flat belting, and one thing that was done was to 'take the belts down' over holidays and summers. The belting was 'run off the pulleys' using a stick or wrench handle, and when the lineshafting stopped spinning, the belts were hung on wire hooks to keep them off the oil shafting. In the old machine shops I worked in, we used to take the belts down over weekends and holidays, and in muggy summer weather, we often took belts down overnight. Leather belting will stretch from humidity in the air, and if left with tension on for any length of time, will 'take a set'. Every shop had a set of belt splicing tools- a Clipper belt lacer, and a Clipper belt cutter (a kind of guillotine hand shear you could carry around to where you needed to shorten a belt). Taking a piece out of a sloppy and stretched belt was a regular occurance.
I got my Cincinnati-Bickford camelback drill well over 25 years ago. It had a loose and sloppy 2" flat leather belt, old as the hills. I figured I'd take the slack out of that belt and cut about 2" out of it. Along the way, I've accumulated assorted lacing hooks, a Clipper belt lacing machine, and a belt cutting shear. I put a new set of hooks on the old flat belt after taking 2" out, and the belt was nice and tight again. I always take that belt down (i.e., run it off the pulleys) when the drill is not in use. I use my camelback drill on an irregular basis and it sits idle for weeks at a time in an unheated garage. In 25 years, that old flat belt has never given me any further problem, running and pulling the drill press nicely, even on heavy work. By contrast, the 1" flat belt for the power feeds is also as old as the main belt, but it was slack and sloppy ages before I got that drill press. Someone smeared thick black belt dressing onto that belt and the cone pulleys for the power quill feed. Sloppy as it is, that belt does the job with the added benefit of slipping if things get overloaded. Even with that slipping feed belt, I blew apart a 1 1/4" counterbore years ago, feeding into 5160 locomotive spring material to open a hole to final size.
Old flat belt driven machinery is what it is. A camelback drill has plain bearings, and lots of other oiling points. It has open gearing. I made up a pump oil can with an extended spout made from 1/4" diameter stainless steel tubing. I machined a nozzle and silbrazed it to the tip of this extended spout. This oil can lets me reach and get into the oiling points on my camelback drill a lot easier. I joke that to drill a hole with my camelback drill, I spend 5 minutes oiling it, a couple of minutes "putting up" the main belt, and another 5-10 minutes 'dogging' the work to the table. I keep a few 1 gallon olive oil tins by the camelback drill with assorted tee nuts, studs, slotted dogs (clamping links), flange-nuts, and some odds and ends of cutoff steel and hardwood. A camelback drill is not your little round column vee belt driven drill. It develops a lot more torque, and clamping work to the table or at least bolting a stop bar to the table is a 'must'. These drills also have a lot of 'stored energy' in their drivelines due to the inertia of the rotating parts. Even in an emergency, there is no stopping these drills instantly, they coast down. If you are hanging onto a job and the drill grabs, a camelback drill is going to wind the job, the vise it was in, and you along with it. Even if you can reach the switch to kill the motor, if you are wound up or pinned by the drill having grabbed the work, the coast-down of the drill will continue to wind or pin and crush whatever part of you it has hold of. An 'emergency stop' switch is not going to be too effective with this type of machine tool.
Sorry to have digressed, but I figure a word to the wise can't hurt. As I wrote, I came up in shops where flat belting was all over the place, and the sounds of belting and lineshafting are music to my ears, but that's just me. In a true lineshaft driven shop, there is a certain music when the lineshafting is in motion. The spokes of the larger pulleys fan the air with a soft whirr. Steel wire rings are often placed on the spans of lineshafting to keep the shafting clean of the grunge from airborne dirt (sawdust if in a woodworking mill, leather dust from the belting, or airborne grinding dust) mixed with oil that migrates out of the lineshaft 'hanger boxes'. As the shafting is transmitting power, it takes an additional deflection due to belt pull, and this combines with the static deflection due to the weight of the pulleys. This deflection causes the wire rings to dance up and back along the spans of shafting, adding a little clinking sound. The belting, particularly wide belts with long runs, tends to slap softly. Then, the clicking of the lacing hooks adds to the music. On belting made up with a belt lacing machine, the hooks are usually pressed into the leather belting so not too much of them is standing proud. The clicking is not a particularly loud sound, but then, I am hard of hearing after over 50 years around machinery and powerplants. When I was a little boy, my parents took me to a woodworking shop run by lineshafting. The owner of the shop was an Amish man, and he was a kindly man with a long white beard who showed me a Stuart model steam engine he'd built. It ran on compressed air alongside his desk, belted to the movement from a music box. He took me on a tour of his woodworking shop. The smell of the fresh cut pine and other woods coupled with the sounds of the lineshafting and belting and the kindly oldtimer (or so it seemed to me back then) with his white beard and Biblical quotes on his office wall all made a lasting impression on me. As little boy, I decided that heaven must be a place peopled with men like that Amish man, men in long white beards and overalls, and heaven had to have a lineshaft driven shop with the sounds of the flat belting and lineshafting. It's been over 60 years since that visit to that shop, and at odd moments, my vision of the hereafter has not changed a whole lot. As I said, to some of us, the sounds of flat belting working and the click of the lacing hooks is sheer music. To others, it is simply noise, but 'to each their own', and differences are what make our world what it is.