4 ms·

When Sprint first built out its digital cellphone network, their slogan was "you can hear a pin drop". It was basically true, this was more clarity and intelli

When Sprint first built out its digital cellphone network, their slogan was "you can hear a pin drop". It was basically true, this was more clarity and intelligibility than the full-quality land line POTS. After a year or two their airwaves got crowded and it became apparent they were compressing the audio enough to be noticeably way worse than the POTS was. Cell carriers seem to have kept performance at that low level ever since. Plus lots of times it seems like it's no longer full-duplex, after a pause more like voice-activated from either end before it starts transmitting to the other party.

smileysteve 3y ago
HD Voice has been rolled out across multiple carriers for a couple of years in the US.
solarkraft 3y ago
It's crazy to me how much telephony still sucks. We can stream 4K video but not some audio in reasonable quality?
- giantrobot 3y ago
  If the audio of a phone call was pre-recorded on a good microphone it could sound awesome even over low bandwidth "voice" connections. Audio for voice calling is optimized almost entirely for latency. This means super short buffers and relatively simple encoding. Streaming video/audio has a distinct advantage of not having the same latency sensitivity. It's not a two way conversation so if the stream is a second or two behind the wall clock as long as it's in sync you're never going to know unless you're watching a stream of an event you can see live, then you'll see the encode and transfer delay. Besides latency, the microphone/audio input pipeline on a phone is in one of the shittiest recording environments it could be in. It's right next to the users mouth, sometimes far too close, so it needs automatic gain control to keep from being overdriven. It also needs to filter out the audio coming from the speaker lest it generates feedback. The microphone itself also needs to be very small and is attacked to the body of the phone so it's difficult to isolate from body sounds like the user's hand rubbing over the body. The fact a cell phone can even transmit reasonable sounding voice is a minor miracle involving many thousands of engineer-hours. The extra processing power and bandwidth available today to handle wideband voice helps a little with quality but it's still very latency sensitive and still suffers vs less latency sensitive codecs or one-way streaming.
- JohnFen 3y ago
  > It's crazy to me how much telephony still sucks. I think about this every time I use make a voice call on a cellphone -- in terms of audio quality, it blows my mind how inferior it is to what we had on POTS lines in the 80s.

smileysteve 3y ago

HD Voice has been rolled out across multiple carriers for a couple of years in the US.

solarkraft 3y ago

It's crazy to me how much telephony still sucks. We can stream 4K video but not some audio in reasonable quality?

giantrobot 3y ago
If the audio of a phone call was pre-recorded on a good microphone it could sound awesome even over low bandwidth "voice" connections. Audio for voice calling is optimized almost entirely for latency. This means super short buffers and relatively simple encoding. Streaming video/audio has a distinct advantage of not having the same latency sensitivity. It's not a two way conversation so if the stream is a second or two behind the wall clock as long as it's in sync you're never going to know unless you're watching a stream of an event you can see live, then you'll see the encode and transfer delay. Besides latency, the microphone/audio input pipeline on a phone is in one of the shittiest recording environments it could be in. It's right next to the users mouth, sometimes far too close, so it needs automatic gain control to keep from being overdriven. It also needs to filter out the audio coming from the speaker lest it generates feedback. The microphone itself also needs to be very small and is attacked to the body of the phone so it's difficult to isolate from body sounds like the user's hand rubbing over the body. The fact a cell phone can even transmit reasonable sounding voice is a minor miracle involving many thousands of engineer-hours. The extra processing power and bandwidth available today to handle wideband voice helps a little with quality but it's still very latency sensitive and still suffers vs less latency sensitive codecs or one-way streaming.
JohnFen 3y ago
> It's crazy to me how much telephony still sucks. I think about this every time I use make a voice call on a cellphone -- in terms of audio quality, it blows my mind how inferior it is to what we had on POTS lines in the 80s.